Cold War

Writer George Orwell used cold war, as a general term, in his essay "You and the Atomic Bomb", published 19 October 1945. Contemplating a world living in the shadow of the threat of nuclear warfare, Orwell looked at James Burnham's predictions of a polarized world, writing:

Looking at the world as a whole, the drift for many decades has been not towards anarchy but towards the reimposition of slavery... James Burnham's theory has been much discussed, but few people have yet considered its ideological implications—that is, the kind of world-view, the kind of beliefs, and the social structure that would probably prevail in a state which was at once unconquerable and in a permanent state of "cold war" with its neighbours.

In The Observer of 10 March 1946, Orwell wrote, "after the Moscow conference last December, Russia began to make a 'cold war' on Britain and the British Empire."

The first use of the term to describe the specific post-war geopolitical confrontation between the Soviet Union and the United States came in a speech by Bernard Baruch, an influential advisor to Democratic presidents, on 16 April 1947. The speech, written by journalist Herbert Bayard Swope, proclaimed, "we are today in the midst of a cold war." Newspaper columnist Walter Lippmann gave the term wide currency with his book The Cold War. When asked in 1947 about the source of the term, Lippmann traced it to a French term from the 1930s, la guerre froide.

Animosity between the Allies of World War II predated the end of the war. The death of Franklin D. Roosevelt in April 1945 and the changeover to Harry Truman's presidential administration led to changes in US-Soviet relations as Truman and his staff began to take a harder diplomatic line. US and Soviet diplomats disputed conflicting interpretations of agreements made between Stalin and Roosevelt at the Yalta Conference. Truman's administration was divided on the question of the Polish government's composition, with Truman and several cabinet members advocating for stronger demands that broader democratic elements be included in its ranks. A 1944 accord between Churchill and Stalin further complicated matters in Eastern Europe; the two had agreed to non-interference in one another's spheres of influence, in Greece and in Romania and Bulgaria respectively. The creation of the United Nations in the spring of 1945 led to further disagreements over how the postwar international order should be governed. Because of the alignment of many Latin American nations with the United States, the Soviets feared that a pro-American majority would be used against them. They opposed the admission of Argentina into the UN, and called for a more expansive Security Council veto. Stalin ultimately accommodated the American positions on the UN veto and on the Polish government, allowing Oskar Lange and Stanisław Mikołajczyk to join it. The abrupt cancellation of the lend-lease in May and the August atomic bombings in Japan, which took place just days before a planned Soviet entry into the Pacific war, further increased tensions.

In February 1946, George F. Kennan's "Long Telegram" from Moscow to Washington helped to articulate the US government's increasingly hard line against the Soviets, which would become the basis for US strategy toward the Soviet Union. The telegram galvanized a policy debate that would eventually shape the Truman administration's Soviet policy. Washington's opposition to the Soviets accumulated after broken promises by Stalin and Molotov concerning Europe and Iran. Following the World War II Anglo-Soviet invasion of Iran, the country was occupied by the Red Army in the far north and the British in the south. Iran was used by the United States and British to supply the Soviet Union, and the Allies agreed to withdraw from Iran within six months after the cessation of hostilities. However, when this deadline came, the Soviets remained in Iran under the guise of the Azerbaijan People's Government and Kurdish Republic of Mahabad. On 5 March, former British prime minister Winston Churchill delivered his famous "Iron Curtain" speech (Fulton Speech) calling for an Anglo-American alliance against the Soviets, whom he accused of establishing an "iron curtain" dividing Europe.

A week later, on 13 March, Stalin responded vigorously to the speech, saying Churchill could be compared to Adolf Hitler insofar as he advocated the racial superiority of English-speaking nations so that they could satisfy their hunger for world domination, and that such a declaration was "a call for war on the USSR." The Soviet leader also dismissed the accusation that the USSR was exerting increasing control over the countries lying in its sphere. He argued that there was nothing surprising in "the fact that the Soviet Union, anxious for its future safety, [was] trying to see to it that governments loyal in their attitude to the Soviet Union should exist in these countries."

Soviet territorial demands to Turkey regarding the Dardanelles in the Turkish Straits crisis and Black Sea border disputes were also a major factor in increasing tensions. In September, the Soviet side produced the Novikov telegram, sent by the Soviet ambassador to the US but commissioned and "co-authored" by Vyacheslav Molotov; it portrayed the US as being in the grip of monopoly capitalists who were building up military capability "to prepare the conditions for winning world supremacy in a new war". On 6 September 1946, James F. Byrnes delivered a speech in Germany repudiating the Morgenthau Plan (a proposal to partition and de-industrialize post-war Germany) and warning the Soviets that the US intended to maintain a military presence in Europe indefinitely. As Byrnes stated a month later, "The nub of our program was to win the German people ... it was a battle between us and Russia over minds ..." In December, the Soviets agreed to withdraw from Iran after persistent US pressure, an early success of containment policy.

By 1947, US president Harry S. Truman was outraged by the perceived resistance of the Soviet Union to American demands in Iran, Turkey, and Greece, as well as Soviet rejection of the Baruch Plan on nuclear weapons. In February 1947, the British government announced that it could no longer afford to finance the Kingdom of Greece against the Communist-led DSE in the Greek Civil War. In the same month, Stalin conducted the rigged 1947 Polish legislative election which constituted an open breach of the Yalta Agreement. The US government responded by adopting a policy of containment, with the goal of stopping the spread of communism. Truman delivered a speech calling for the allocation of $400 million to intervene in the war and unveiled the Truman Doctrine, which framed the conflict as a contest between free peoples and totalitarian regimes. American policymakers accused the Soviet Union of conspiring against the Greek royalists in an effort to expand Soviet influence even though Stalin had told the Communist Party to cooperate with the British-backed government.

Enunciation of the Truman Doctrine marked the beginning of a US bipartisan defense and foreign policy consensus between Republicans and Democrats focused on containment and deterrence that weakened during and after the Vietnam War, but ultimately persisted thereafter. Moderate and conservative parties in Europe, as well as social democrats, gave virtually unconditional support to the Western alliance, while European and American Communists, financed by the KGB and involved in its intelligence operations, adhered to Moscow's line, although dissent began to appear after 1956. Other critiques of the consensus policy came from anti-Vietnam War activists, the Campaign for Nuclear Disarmament, and the anti-nuclear movement.

In early 1947, France, Britain and the United States unsuccessfully attempted to reach an agreement with the Soviet Union for a plan envisioning an economically self-sufficient Germany, including a detailed accounting of the industrial plants, goods and infrastructure already taken by the Soviets. In June 1947, in accordance with the Truman Doctrine, the United States enacted the Marshall Plan, a pledge of economic assistance for all European countries willing to participate. Under the plan, which President Harry S. Truman signed on 3 April 1948, the US government gave to Western European countries over $13 billion (equivalent to $189 billion in 2016). Later, the program led to the creation of the OECD.

The plan's aim was to rebuild the democratic and economic systems of Europe and to counter perceived threats to the European balance of power, such as communist parties seizing control. The plan also stated that European prosperity was contingent upon German economic recovery. One month later, Truman signed the National Security Act of 1947, creating a unified Department of Defense, the Central Intelligence Agency (CIA), and the National Security Council (NSC). These would become the main bureaucracies for US defense policy in the Cold War.

Stalin believed economic integration with the West would allow Eastern Bloc countries to escape Soviet control, and that the US was trying to buy a pro-US re-alignment of Europe. Stalin therefore prevented Eastern Bloc nations from receiving Marshall Plan aid. The Soviet Union's alternative to the Marshall Plan, which was purported to involve Soviet subsidies and trade with central and eastern Europe, became known as the Molotov Plan (later institutionalized in January 1949 as the Council for Mutual Economic Assistance). Stalin was also fearful of a reconstituted Germany; his vision of a post-war Germany did not include the ability to rearm or pose any kind of threat to the Soviet Union.

In early 1948, Czech Communists executed a coup d'état in Czechoslovakia (resulting in the formation of the Czechoslovak Socialist Republic), the only Eastern Bloc state that the Soviets had permitted to retain democratic structures. The public brutality of the coup shocked Western powers more than any event up to that point and swept away the last vestiges of opposition to the Marshall Plan in the United States Congress.

In an immediate aftermath of the crisis, the London Six-Power Conference was held, resulting in the Soviet boycott of the Allied Control Council and its incapacitation, an event marking the beginning of the full-blown Cold War, as well as ending any hopes at the time for a single German government and leading to formation in 1949 of the Federal Republic of Germany and German Democratic Republic.

The twin policies of the Truman Doctrine and the Marshall Plan led to billions in economic and military aid for Western Europe, Greece, and Turkey. With the US assistance, the Greek military won its civil war. Under the leadership of Alcide De Gasperi the Italian Christian Democrats defeated the powerful Communist–Socialist alliance in the elections of 1948, with covert support from the United States.

Outside of Europe, the United States also began to express interest in the development of many other countries, so that they would not fall under the sway of Eastern Bloc communism. In his January 1949 inaugural address, Truman declared for the first time in US history that international development would be a key part of US foreign policy. The resulting program later became known as the Point Four Program because it was the fourth point raised in his address.

All major powers engaged in espionage, using a great variety of spies, double agents, moles, and new technologies such as the tapping of telephone cables. The Soviet KGB ("Committee for State Security"), the bureau responsible for foreign espionage and internal surveillance, was famous for its effectiveness. The most famous Soviet operation involved its atomic spies that delivered crucial information from the United States' Manhattan Project, leading the USSR to detonate its first nuclear weapon in 1949, four years after the American detonation and much sooner than expected. A massive network of informants throughout the Soviet Union was used to monitor dissent from official Soviet politics and morals. Although to an extent disinformation had always existed, the term itself was invented, and the strategy formalized by a black propaganda department of the Soviet KGB.

Based on the amount of top-secret Cold War archival information that has been released, historian Raymond L. Garthoff concludes there probably was parity in the quantity and quality of secret information obtained by each side. However, the Soviets probably had an advantage in terms of HUMINT (human intelligence or interpersonal espionage) and "sometimes in its reach into high policy circles." In terms of decisive impact, however, he concludes:

We also can now have high confidence in the judgment that there were no successful "moles" at the political decision-making level on either side. Similarly, there is no evidence, on either side, of any major political or military decision that was prematurely discovered through espionage and thwarted by the other side. There also is no evidence of any major political or military decision that was crucially influenced (much less generated) by an agent of the other side.

According to historian Robert L. Benson, "Washington's forte was 'signals' intelligence – the procurement and analysis of coded foreign messages," leading to the Venona project or Venona intercepts, which monitored the communications of Soviet intelligence agents. Moynihan wrote that the Venona project contained "overwhelming proof of the activities of Soviet spy networks in America, complete with names, dates, places, and deeds." The Venona project was kept highly secret even from policymakers until the Moynihan Commission in 1995. Despite this, the decryption project had already been betrayed and dispatched to the USSR by Kim Philby and Bill Weisband in 1946, as was discovered by the US by 1950. Nonetheless, the Soviets had to keep their discovery of the program secret, too, and continued leaking their own information, some of which was still useful to the American program. According to Moynihan, even President Truman may not have been fully informed of Venona, which may have left him unaware of the extent of Soviet espionage.

Clandestine atomic spies from the Soviet Union, who infiltrated the Manhattan Project during WWII, played a major role in increasing tensions that led to the Cold War.

In addition to usual espionage, the Western agencies paid special attention to debriefing Eastern Bloc defectors. Edward Jay Epstein describes that the CIA understood that the KGB used "provocations", or fake defections, as a trick to embarrass Western intelligence and establish Soviet double agents. As a result, from 1959 to 1973, the CIA required that East Bloc defectors went through a counterintelligence investigation before being recruited as a source of intelligence.

During the late 1970s and 1980s, the KGB perfected its use of espionage to sway and distort diplomacy.

In 1953, changes in political leadership on both sides shifted the dynamic of the Cold War. Dwight D. Eisenhower was inaugurated president that January. During the last 18 months of the Truman administration, the American defense budget had quadrupled, and Eisenhower moved to reduce military spending by a third while continuing to fight the Cold War effectively.

Joseph Stalin died in 1953. Nikita Khrushchev eventually won the ensuing power struggle by the mid-1950s. In 1956, he denounced Joseph Stalin and proceeded to ease controls over the party and society (de-Stalinization).

On 18 November 1956, while addressing Western dignitaries at a reception in Moscow's Polish embassy, Khrushchev infamously declared, "Whether you like it or not, history is on our side. We will bury you", shocking everyone present. He would later clarify he had not been referring to nuclear war, but the "historically fated victory of communism over capitalism."

Eisenhower's secretary of state, John Foster Dulles, initiated a "New Look" for the containment strategy, calling for a greater reliance on nuclear weapons against US enemies in wartime. Dulles also enunciated the doctrine of "massive retaliation", threatening a severe US response to any Soviet aggression. Possessing nuclear superiority, for example, allowed Eisenhower to face down Soviet threats to intervene in the Middle East during the 1956 Suez Crisis. The declassified US plans for retaliatory nuclear strikes in the late 1950s included the "systematic destruction" of 1,200 major urban centers in the Soviet Bloc and China, including Moscow, East Berlin and Beijing.

In spite of these events, there were substantial hopes for détente when an upswing in diplomacy took place in 1959, including a two-week visit by Khrushchev to the US, and plans for a two-power summit for May 1960. The latter was disturbed by the U-2 spy plane scandal, however, in which Eisenhower was caught lying about the intrusion of American surveillance aircraft into Soviet territory.

While Stalin's death in 1953 slightly relaxed tensions, the situation in Europe remained an uneasy armed truce. The Soviets, who had already created a network of mutual assistance treaties in the Eastern Bloc by 1949, established a formal alliance therein, the Warsaw Pact, in 1955. It stood opposed to NATO.

The Hungarian Revolution of 1956 occurred shortly after Khrushchev arranged the removal of Hungary's Stalinist leader Mátyás Rákosi. In response to a popular anti-communist uprising, the new regime formally disbanded the secret police, declared its intention to withdraw from the Warsaw Pact and pledged to re-establish free elections. The Soviet Army invaded. Thousands of Hungarians were killed and arrested, imprisoned and deported to the Soviet Union, and approximately 200,000 Hungarians fled Hungary. Hungarian leader Imre Nagy and others were executed following secret trials.

From 1957 through 1961, Khrushchev openly and repeatedly threatened the West with nuclear annihilation. He claimed that Soviet missile capabilities were far superior to those of the United States, capable of wiping out any American or European city. According to John Lewis Gaddis, Khrushchev rejected Stalin's "belief in the inevitability of war," however. The new leader declared his ultimate goal was "peaceful coexistence". In Khrushchev's formulation, peace would allow capitalism to collapse on its own, as well as giving the Soviets time to boost their military capabilities, which remained for decades until Gorbachev's later "new thinking" envisioning peaceful coexistence as an end in itself rather than a form of class struggle.

The events in Hungary produced ideological fractures within the communist parties of the world, particularly in Western Europe, with great decline in membership, as many in both western and socialist countries felt disillusioned by the brutal Soviet response. The communist parties in the West would never recover.

In 1957, Polish foreign minister Adam Rapacki proposed the Rapacki Plan for a nuclear free zone in central Europe. Public opinion tended to be favourable in the West, but it was rejected by leaders of West Germany, Britain, France and the United States. They feared it would leave the powerful conventional armies of the Warsaw Pact dominant over the weaker NATO armies.

During November 1958, Khrushchev made an unsuccessful attempt to turn all of Berlin into an independent, demilitarized "free city". He gave the United States, Great Britain and France a six-month ultimatum to withdraw their troops from the sectors of West Berlin, or he would transfer control of Western access rights to the East Germans. Khrushchev earlier explained to Mao Zedong that "Berlin is the testicles of the West. Every time I want to make the West scream, I squeeze on Berlin." NATO formally rejected the ultimatum in mid-December and Khrushchev withdrew it in return for a Geneva conference on the German question.

Like Truman and Eisenhower, John F. Kennedy supported containment. President Eisenhower's New Look policy had emphasized the use of less expensive nuclear weapons to deter Soviet aggression by threatening massive nuclear attacks on all of the Soviet Union. Nuclear weapons were much cheaper than maintaining a large standing army, so Eisenhower cut conventional forces to save money. Kennedy implemented a new strategy known as flexible response. This strategy relied on conventional arms to achieve limited goals. As part of this policy, Kennedy expanded the United States special operations forces, elite military units that could fight unconventionally in various conflicts. Kennedy hoped that the flexible response strategy would allow the US to counter Soviet influence without resorting to nuclear war.

To support his new strategy, Kennedy ordered a massive increase in defense spending and a rapid build-up of the nuclear arsenal to restore the lost superiority over the Soviet Union. In his inaugural address, Kennedy promised "to bear any burden" in the defense of liberty, and he repeatedly asked for increases in military spending and authorization of new weapons systems. From 1961 to 1964, the number of nuclear weapons increased by 50 percent, as did the number of B-52 bombers to deliver them. The new ICBM force grew from 63 intercontinental ballistic missiles to 424. He authorized 23 new Polaris submarines, each of which carried 16 nuclear missiles. Kennedy also called on cities to construct fallout shelters.

Economist Adam Hanieh argues that, in the post-WWII era, the global capitalist system was destabilized by a wave of decolonization movements that swept through Africa, Asia, and Latin America. According to historian L. S. Stavrianos, inspired by the Soviet Union’s rapid socioeconomic progress, numerous revolutionary governments subsequently implemented state-planned economies and public ownership. In his autobiography, the former Prime Minister of India, Jawaharlal Nehru, proclaimed that "the presence and example of the Soviets was a bright and heartening phenomenon in a dark and dismal world." Political scientist Michael Parenti argues that these revolutionary governments implemented land reform and comprehensive programs for health, education, housing, and employment. By addressing the legacies of colonial exploitation and extreme poverty, he writes, these initiatives resulted in a historically unprecedented rise in the standard of living for hundreds of millions of people. Economist Samir Amin contends that these revolutionary governments also achieved progress in industrialization, economic equality, and the construction of modern states. According to economist Alice Amsden, World Bank data reveal a historic trend between 1950 and 1980: for the first time in recorded history, developing economies outpaced developed economies, achieving an average annual income growth of over 5% compared to 4% in the developed economies. She described this era as "a period of unprecedented expansion in living standards, per capita income, wages, and poverty reduction."

Political scientist Michael Parenti argues that the U.S. launched a global "counter-revolution" to suppress the rise of revolutionary nationalist governments in the Third World, involving direct military interventions, coups, funding opposition movements, and the training of military forces. Historian Dov H. Levin notes that, between 1946 and 2000, the U.S. interfered in the elections of 81 countries. According to Mark Curtis, the U.S. and other NATO allies actively backed fundamentalist Islamist movements throughout the Middle East, North Africa, and Central and Southern Asia. These movements were seen as a strategic buffer against Soviet influence and a counterforce to nationalist and socialist movements. This policy was formalized at the highest levels during the Arab Cold War, when, in 1957, President Eisenhower approved a policy to "do everything possible to stress the 'holy war' aspect." Reflecting on this policy decades later, Saudi Crown Prince Mohammed bin Salman said in 2018 that the international spread of Saudi Wahhabism was "rooted in the Cold War, when allies asked Saudi Arabia to use its resources to prevent inroads in Muslim countries by the Soviet Union."

Nationalist movements in some countries and regions, notably Guatemala, Indonesia and Indochina, were often allied with Communist groups or otherwise perceived to be unfriendly to Western interests. In this context, the United States and the Soviet Union increasingly competed for influence by proxy in the Third World as decolonization gained momentum in the 1950s and early 1960s. Both sides were selling armaments to gain influence. The Kremlin saw continuing territorial losses by imperial powers as presaging the eventual victory of their ideology.

The United States used the Central Intelligence Agency (CIA) to undermine neutral or hostile Third World governments and to support allied ones. In 1953, President Eisenhower implemented Operation Ajax, a covert coup operation to overthrow the Iranian prime minister, Mohammad Mosaddegh. The popularly elected Mosaddegh had been a Middle Eastern nemesis of Britain since nationalizing the British-owned Anglo-Iranian Oil Company in 1951. Winston Churchill told the United States that Mosaddegh was "increasingly turning towards Communist influence." The pro-Western shah, Mohammad Reza Pahlavi, assumed control as an autocratic monarch. The shah's policies included banning the communist Tudeh Party of Iran, and general suppression of political dissent by SAVAK, the shah's domestic security and intelligence agency.

In Guatemala, a banana republic, the 1954 Guatemalan coup d'état ousted the left-wing President Jacobo Árbenz with material CIA support. The post-Arbenz government—a military junta headed by Carlos Castillo Armas—repealed a progressive land reform law, returned nationalized property belonging to the United Fruit Company, set up a National Committee of Defense Against Communism, and decreed a Preventive Penal Law Against Communism at the request of the United States.

The non-aligned Indonesian government of Sukarno was faced with a major threat to its legitimacy beginning in 1956 when several regional commanders began to demand autonomy from Jakarta. After mediation failed, Sukarno took action to remove the dissident commanders. In February 1958, dissident military commanders in Central Sumatra (Colonel Ahmad Husein) and North Sulawesi (Colonel Ventje Sumual) declared the Revolutionary Government of the Republic of Indonesia-Permesta Movement aimed at overthrowing the Sukarno regime. They were joined by many civilian politicians from the Masyumi Party, such as Sjafruddin Prawiranegara, who were opposed to the growing influence of the communist Partai Komunis Indonesia.

In the course of the 1960s and 1970s, Cold War participants struggled to adjust to a new, more complicated pattern of international relations in which the world was no longer divided into two clearly opposed blocs. From the beginning of the post-war period with American help, Western Europe and Japan rapidly recovered from the destruction of World War II and sustained strong economic growth throughout the 1950s and 1960s, with per capita GDPs approaching those of the United States, while Eastern Bloc economies stagnated.

In Indonesia, the hardline anti-communist General Suharto wrested control from predecessor Sukarno in an attempt to establish a "New Order". From 1965 to 1966, with the aid of the US and other Western governments, the military led the mass killing of more than 500,000 members and sympathizers of the Indonesian Communist Party and other leftist organizations, and detained hundreds of thousands in prison camps under inhumane conditions. A top-secret CIA report stated that the massacres "rank as one of the worst mass murders of the 20th century, along with the Soviet purges of the 1930s, the Nazi mass murders during the Second World War, and the Maoist bloodbath of the early 1950s." These killings served US interests and constitute a major turning point in the Cold War as the balance of power shifted in Southeast Asia.

The Vietnam War descended into a quagmire for the United States, leading to a decline in international prestige and economic stability, derailing arms agreements, and provoking domestic unrest. America's withdrawal from the war led it to embrace a policy of détente with both China and the Soviet Union.

Backed by the Kampuchean United Front for National Salvation, an organization of Khmer pro-Soviet Communists and Khmer Rouge defectors, Vietnam invaded Cambodia on 22 December 1978. The invasion succeeded in deposing Pol Pot, but the new state struggled to gain international recognition beyond the Soviet Bloc sphere. Despite the international outcry at the Pol Pot regime's gross human rights violations, representatives of the Khmer Rouge were allowed to be seated in the UN General Assembly, with strong support from China, the Western powers, and the member countries of ASEAN. Following the destruction of the Khmer Rouge, the national reconstruction of Cambodia was hampered, and Vietnam suffered a punitive Chinese attack. Although unable to deter Vietnam from ousting Pol Pot, China demonstrated that its Cold War communist adversary, the Soviet Union, was unable to protect its Vietnamese ally. Former U.S. Secretary of State Henry Kissinger wrote that "China succeeded in exposing the limits of...[Soviet] strategic reach" and speculated that the desire to "compensate for their ineffectuality" contributed to the Soviets' decision to intervene in Afghanistan a year later.

In the 1973 oil crisis, Organization of Petroleum Exporting Countries (OPEC) cut their petroleum output. This raised oil prices and hurt Western economies, but helped the Soviet Union by generating a huge flow of money from its oil sales.

As a result of the oil crisis, combined with the growing influence of Third World alignments, such as OPEC and the Non-Aligned Movement, less powerful countries had more room to assert their independence and often showed themselves resistant to pressure from either superpower. Meanwhile, Moscow was forced to turn its attention inward to deal with the Soviet Union's deep-seated domestic economic problems. During this period, Soviet leaders such as Leonid Brezhnev and Alexei Kosygin embraced the notion of détente.

Under President John F. Kennedy, US troop levels in Vietnam grew from just under a thousand in 1959 to 16,000 in 1963. South Vietnamese President Ngo Dinh Diem's heavy-handed crackdown on Buddhist monks in 1963 led the US to endorse a deadly military coup against Diem. The war escalated further in 1964 following the controversial Gulf of Tonkin incident, in which a US destroyer was alleged to have clashed with North Vietnamese fast attack craft. The Gulf of Tonkin Resolution gave President Lyndon B. Johnson broad authorization to increase US military presence, deploying ground combat units for the first time and increasing troop levels to 184,000. Soviet leader Leonid Brezhnev responded by reversing Khrushchev's policy of disengagement and increasing aid to the North Vietnamese, hoping to entice the North from its pro-Chinese position. The USSR discouraged further escalation of the war, however, providing just enough military assistance to tie up American forces. From this point, the People's Army of Vietnam (PAVN) engaged in more conventional warfare with US and South Vietnamese forces.

The Tet Offensive of 1968 proved to be the turning point of the war. Despite years of American tutelage and aid, the South Vietnamese forces were unable to withstand the communist offensive and the task fell to US forces instead. At the same time, in 1963–1965, American domestic politics saw the triumph of liberalism. According to historian Joseph Crespino:

It has become a staple of twentieth-century historiography that Cold War concerns were at the root of a number of progressive political accomplishments in the postwar period: a high progressive marginal tax rate that helped fund the arms race and contributed to broad income equality; bipartisan support for far-reaching civil rights legislation that transformed politics and society in the American South, which had long given the lie to America's egalitarian ethos; bipartisan support for overturning an explicitly racist immigration system that had been in place since the 1920s; and free health care for the elderly and the poor, a partial fulfillment of one of the unaccomplished goals of the New Deal era. The list could go on.

The Partial Nuclear Test Ban Treaty was signed on August 5, 1963, by the United States, the Soviet Union, and over 100 other nations. This treaty banned nuclear weapons tests in the atmosphere, outer space, and underwater, restricting such tests to underground environments. The treaty followed heightened concerns over the militarization of space, amplified by the United States' Starfish Prime test in 1962, which involved the detonation of a nuclear device in the upper atmosphere.

To further delineate the peaceful use of outer space, the United Nations facilitated the drafting of the Treaty on Principles Governing the Activities of States in the Exploration and Use of Outer Space, including the Moon and Other Celestial Bodies, commonly known as the Outer Space Treaty. Signed on January 27, 1967, by the United States, the Soviet Union, and the United Kingdom, it entered into force on October 10, 1967. The treaty established space as a domain to be used exclusively for peaceful purposes, prohibiting the placement of nuclear weapons or any other weapons of mass destruction in orbit or on celestial bodies.

In 1968, a period of political liberalization took place in Czechoslovakia called the Prague Spring. An "Action Program" of reforms included increasing freedom of the press, freedom of speech and freedom of movement, along with an economic emphasis on consumer goods, the possibility of a multiparty government, limitations on the power of the secret police, and potential withdrawal from the Warsaw Pact.

In answer to the Prague Spring, on 20 August 1968, the Soviet Army, together with most of their Warsaw Pact allies, invaded Czechoslovakia. The invasion was followed by a wave of emigration, including an estimated 70,000 Czechs and Slovaks initially fleeing, with the total eventually reaching 300,000. The invasion sparked intense protests from Yugoslavia, Romania, China, and from Western European countries.

As a result of the Sino-Soviet split, tensions along the Chinese–Soviet border reached their peak in 1969, when the Soviet planned to launch a large-scale nuclear strike against China. United States President Richard Nixon intervened, and decided to use the conflict to shift the balance of power towards the West in the Cold War through a policy of rapproachment with China, which began with his 1972 visit to China and culminated in 1979 with the signing of the Joint Communiqué on the Establishment of Diplomatic Relations by President Carter and Chinese Communist Party leader Deng Xiaoping.

Although indirect conflict between Cold War powers continued through the late 1960s and early 1970s, tensions were beginning to ease. Following the ousting of Khrushchev, another period of collective leadership ensued, consisting of Leonid Brezhnev as general secretary, Alexei Kosygin as Premier and Nikolai Podgorny as Chairman of the Presidium, lasting until Brezhnev established himself in the early 1970s as the preeminent Soviet leader.

Following his visit to China, Nixon met with Soviet leaders in Moscow. These Strategic Arms Limitation Talks resulted in landmark arms control treaties. These aimed to limit the development of costly anti-ballistic missiles and nuclear missiles.

Nixon and Brezhnev proclaimed a new era of "peaceful coexistence" and established the groundbreaking new policy of détente (or cooperation) between the superpowers. Meanwhile, Brezhnev attempted to revive the Soviet economy, which was declining in part because of heavy military expenditures. The Soviet Union's military budget in the 1970s was massive, 40–60% of the federal budget and 15% of GDP. Between 1972 and 1974, the two sides also agreed to strengthen their economic ties, including agreements for increased trade. As a result of their meetings, détente would replace the hostility of the Cold War and the two countries would live mutually. These developments coincided with Bonn's Ostpolitik policy formulated by the West German Chancellor Willy Brandt, an effort to normalize relations between West Germany and Eastern Europe. Other agreements were concluded to stabilize the situation in Europe, culminating in the Helsinki Accords signed at the Conference on Security and Co-operation in Europe in 1975.

The Helsinki Accords, in which the Soviets promised to grant free elections in Europe, has been called a major concession to ensure peace by the Soviets. In practice, the Soviet government significantly curbed the rule of law, civil liberties, protection of law, and guarantees of property, which were considered examples of "bourgeois morality" by Soviet legal theorists such as Andrey Vyshinsky. The Soviet Union signed legally-binding human rights documents, such as the International Covenant on Civil and Political Rights in 1973 and the Helsinki Accords in 1975, but they were neither widely known or accessible to people living under communist rule, nor were they taken seriously by the communist authorities. Human rights activists in the Soviet Union were regularly subjected to harassment, repressions and arrests.

The pro-Soviet American business magnate Armand Hammer of Occidental Petroleum often mediated trade relations. Author Daniel Yergin, in his book The Prize, writes that Hammer "ended up as a go-between for five Soviet General Secretaries and seven US Presidents." Hammer had extensive business relationship in the Soviet Union stretching back to the 1920s with Lenin's approval. According to Christian Science Monitor in 1980, "although his business dealings with the Soviet Union were cut short when Stalin came to power, he had more or less single-handedly laid the groundwork for the state of Western trade with the Soviet Union."

Kissinger and Nixon were "realists" who deemphasized idealistic goals like anti-communism or promotion of democracy worldwide because those goals were too expensive in terms of America's economic capabilities. They rejected "idealism" as impractical and too expensive, and neither man showed much sensitivity to the plight of people living under communism.

The period in the late 1970s and early 1980s showed an intensive reawakening of Cold War tensions and conflicts. Tensions greatly increased between the major powers with both sides becoming more militant. Diggins says, "Reagan went all out to fight the second cold war, by supporting counterinsurgencies in the third world." Cox says, "The intensity of this 'second' Cold War was as great as its duration was short."

In April 1978, the communist People's Democratic Party of Afghanistan (PDPA) seized power in Afghanistan in the Saur Revolution. Within months, opponents of the communist regime launched an uprising in eastern Afghanistan that quickly expanded into a civil war waged by guerrilla mujahideen against government forces countrywide. The Islamic Unity of Afghanistan Mujahideen insurgents received military training and weapons in neighboring Pakistan and China, while the Soviet Union sent thousands of military advisers to support the PDPA government. Meanwhile, increasing friction between the competing factions of the PDPA—the dominant Khalq and the more moderate Parcham—resulted in the dismissal of Parchami cabinet members and the arrest of Parchami military officers under the pretext of a Parchami coup. By mid-1979, the United States had started a covert program to assist the mujahideen.

In September 1979, Khalqist President Nur Muhammad Taraki was assassinated in a coup within the PDPA orchestrated by fellow Khalq member Hafizullah Amin, who assumed the presidency. Distrusted by the Soviets, Amin was assassinated by Soviet special forces during Operation Storm-333 in December 1979. Afghan forces suffered losses during the Soviet operation; 30 Afghan palace guards and over 300 army guards were killed while another 150 were captured. In the aftermath of the operation, a total of 1,700 Afghan soldiers who surrendered to Soviet forces were taken as prisoners, and the Soviets installed Babrak Karmal, the leader of the PDPA's Parcham faction, as Amin's successor. Veterans of the Soviet Union's Alpha Group have stated that Operation Storm-333 was one of the most successful in the unit's history. Documents released following the dissolution of the Soviet Union in the 1990s revealed that the Soviet leadership believed Amin had secret contacts within the American embassy in Kabul and "was capable of reaching an agreement with the United States"; however, allegations of Amin colluding with the Americans have been widely discredited. The PDBA was tasked to fill the vacuum and carried out a purge of Amin supporters. Soviet troops were deployed to put Afghanistan under Soviet control with Karmal in more substantial numbers, although the Soviet government did not expect to do most of the fighting in Afghanistan. As a result, however, the Soviets were now directly involved in what had been a domestic war in Afghanistan.

Carter responded to the Soviet invasion by withdrawing the SALT II treaty from ratification, imposing embargoes on grain and technology shipments to the USSR, and demanding a significant increase in military spending, and further announced the boycott of the 1980 Summer Olympics in Moscow, which was joined by 65 other nations. He described the Soviet incursion as "the most serious threat to the peace since the Second World War".

In January 1977, four years prior to becoming president, Ronald Reagan bluntly stated, in a conversation with Richard V. Allen, his basic expectation in relation to the Cold War. "My idea of American policy toward the Soviet Union is simple, and some would say simplistic," he said. "It is this: We win and they lose." In 1980, Ronald Reagan won the 1980 presidential election, vowing to increase military spending and confront the Soviets everywhere. Both Reagan and new British Prime Minister Margaret Thatcher denounced the Soviet Union and its ideology. Reagan labeled the Soviet Union an "evil empire" and predicted that communism would be left on the "ash heap of history," while Thatcher inculpated the Soviets as "bent on world dominance." In 1982, Reagan tried to cut off Moscow's access to hard currency by impeding its proposed gas line to Western Europe. It hurt the Soviet economy, but it also caused ill will among American allies in Europe who counted on that revenue. Reagan retreated on this issue.

By early 1985, Reagan's anti-communist position had developed into a stance known as the new Reagan Doctrine—which, in addition to containment, formulated an additional right to subvert existing communist governments. Besides continuing Carter's policy of supporting the Islamic opponents of the Soviet Union and the Soviet-backed PDPA government in Afghanistan, the CIA also sought to weaken the Soviet Union itself by promoting Islamism in the majority-Muslim Central Asian Soviet Union. Additionally, the CIA encouraged anti-communist Pakistan's ISI to train Muslims from around the world to participate in the jihad against the Soviet Union.

Pope John Paul II provided a moral focus for anti-communism; a visit to his native Poland in 1979 stimulated a religious and nationalist resurgence centered on the Solidarity movement trade union that galvanized opposition, and may have led to his attempted assassination two years later. In December 1981, Poland's Wojciech Jaruzelski reacted to the crisis by imposing a period of martial law. Reagan imposed economic sanctions on Poland in response. Mikhail Suslov, the Kremlin's top ideologist, advised Soviet leaders not to intervene if Poland fell under the control of Solidarity, for fear it might lead to heavy economic sanctions, resulting in a catastrophe for the Soviet economy.

The Soviet Union had built up a military that consumed as much as 25 percent of its gross national product at the expense of consumer goods and investment in civilian sectors. Soviet spending on the arms race and other Cold War commitments both caused and exacerbated deep-seated structural problems in the Soviet system, which experienced at least a decade of economic stagnation during the late Brezhnev years.

Soviet investment in the defense sector was not driven by military necessity but in large part by the interests of the nomenklatura, which was dependent on the sector for their own power and privileges. The Soviet Armed Forces became the largest in the world in terms of the numbers and types of weapons they possessed, in the number of troops in their ranks, and in the sheer size of their military–industrial base. However, the quantitative advantages held by the Soviet military often concealed areas where the Eastern Bloc dramatically lagged behind the West. For example, the Persian Gulf War demonstrated how the armor, fire control systems, and firing range of the Soviet Union's most common main battle tank, the T-72, were drastically inferior to the American M1 Abrams, yet the USSR fielded almost three times as many T-72s as the US deployed M1s.

By the early 1980s, the USSR had built up a military arsenal and army surpassing that of the United States. Soon after the Soviet invasion of Afghanistan, President Carter began massively building up the United States military. This buildup was accelerated by the Reagan administration, which increased the military spending from 5.3 percent of GNP in 1981 to 6.5 percent in 1986, the largest peacetime defense buildup in United States history. The American-Soviet tensions present during 1983 was defined by some as the start of "Cold War II". While in retrospective this phase of the Cold War was generally defined as a "war of words", the Soviet's "peace offensive" was largely rejected by the West.

Tensions continued to intensify as Reagan revived the B-1 Lancer program, which had been canceled by the Carter administration, produced LGM-118 Peacekeeper missiles, installed US cruise missiles in Europe, and announced the experimental Strategic Defense Initiative, dubbed "Star Wars" by the media, a defense program to shoot down missiles in mid-flight. The Soviets deployed RSD-10 Pioneer ballistic missiles targeting Western Europe, and NATO decided, under the impetus of the Carter presidency, to deploy MGM-31 Pershing and cruise missiles in Europe, primarily West Germany. This deployment placed missiles just 10 minutes' striking distance from Moscow.

After Reagan's military buildup, the Soviet Union did not respond by further building its military, because the enormous military expenses, along with inefficient planned manufacturing and collectivized agriculture, were already a heavy burden for the Soviet economy. At the same time, Saudi Arabia increased oil production, even as other non-OPEC nations were increasing production. These developments contributed to the 1980s oil glut, which affected the Soviet Union as oil was the main source of Soviet export revenues. Issues with command economics, oil price decreases and large military expenditures gradually brought the Soviet economy to stagnation.

On 1 September 1983, the Soviet Union shot down Korean Air Lines Flight 007, a Boeing 747 with 269 people aboard, including sitting Congressman Larry McDonald, an action which Reagan characterized as a massacre. The airliner was en route from Anchorage to Seoul but owing to a navigational mistake made by the crew, it flew through Russian prohibited airspace. The Soviet Air Force treated the unidentified aircraft as an intruding U.S. spy plane and destroyed it with air-to-air missiles. The incident increased support for military deployment, overseen by Reagan, which stood in place until the later accords between Reagan and Mikhail Gorbachev. During the early hours of 26 September 1983, the 1983 Soviet nuclear false alarm incident occurred; systems in Serpukhov-15 underwent a glitch that claimed several intercontinental ballistic missiles were heading towards Russia, but officer Stanislav Petrov correctly suspected it was a false alarm, ensuring the Soviets did not respond to the non-existent attack. As such, he has been credited as "the man who saved the world". The Able Archer 83 exercise in November 1983, a realistic simulation of a coordinated NATO nuclear release, was perhaps the most dangerous moment since the Cuban Missile Crisis, as the Soviet leadership feared that a nuclear attack might be imminent.

American domestic public concerns about intervening in foreign conflicts persisted from the end of the Vietnam War. The Reagan administration emphasized the use of quick, low-cost counterinsurgency tactics to intervene in foreign conflicts. In 1983, the Reagan administration intervened in the multisided Lebanese Civil War, invaded Grenada, bombed Libya and backed the Central American Contras, anti-communist paramilitaries seeking to overthrow the Soviet-aligned Sandinista government in Nicaragua. While Reagan's interventions against Grenada and Libya were popular in the United States, his backing of the Contra rebels was mired in controversy. The Reagan administration's backing of the military government of Guatemala during the Guatemalan Civil War, in particular the regime of Efraín Ríos Montt, was also controversial.

Meanwhile, the Soviets incurred high costs for their own foreign interventions. Although Brezhnev was convinced in 1979 that the Soviet war in Afghanistan would be brief, Muslim guerrillas, aided by the US, China, Britain, Saudi Arabia, and Pakistan, waged a fierce resistance against the invasion. The Kremlin sent nearly 100,000 troops to support its puppet regime in Afghanistan, leading many outside observers to dub the war "the Soviets' Vietnam". However, Moscow's quagmire in Afghanistan was far more disastrous for the Soviets than Vietnam had been for the Americans because the conflict coincided with a period of internal decay and domestic crisis in the Soviet system.

A senior US State Department official predicted such an outcome as early as 1980, positing that the invasion resulted in part from a:

...domestic crisis within the Soviet system. ...