Cold War is the state of conflict, tension and competition that existed between the United States and the Soviet Union (USSR) and their respective allies from the mid-1940s to the early 1990s. Throughout this period, rivalry between the two superpowers was expressed through military coalitions, propaganda, espionage, weapons development, industrial advances, and competitive technological development, e.g., the space race. Both superpowers engaged in costly defence spending, a massive conventional and nuclear arms race, and numerous proxy wars.
In the absence of a declared war between the US and the Soviet Union, the rival states participated in a half-century of military buildup and political battles for support around the world. These activities included the significant involvement of allied and satellite nations in local "third party" wars. Although the US and the Soviet Union had been allied against the Axis powers, the two sides differed on how to reconstruct the postwar world even before the end of World War II. During the next few decades, the Cold War spread beyond Europe to every region of the world, as the US sought the "containment" and "rollback" of communism and forged myriad alliances to this end, particularly in Western Europe and the Middle East. Meanwhile, the Soviet Union fostered Communist movements around the world, particularly in Eastern Europe, Latin America and Southeast Asia.
The Cold War period was characterized by international crises such as the Berlin Blockade (1948–49), the Korean War (1950–53), the Berlin Crisis of 1961, the Vietnam War (1959–1975), the Soviet-Afghan War (1979–89), and especially the 1962 Cuban Missile Crisis, when the world came to the brink of a Third World War. The last such crisis moment occurred during NATO exercises in November 1983. The Cold War era also witnessed periods of reduced tension as both sides sought détente. Direct military attacks on adversaries were deterred by the potential for mutual assured destruction using deliverable nuclear weapons.
The Cold War drew to a close in the late 1980s and the early 1990s. With the coming to power of US President Ronald Reagan, the US increased diplomatic, military, and economic pressure on the Soviet Union. In the second half of the 1980s, newly appointed Soviet leader Mikhail Gorbachev introduced perestroika and glasnost. The Soviet Union collapsed in 1991, leaving the United States as the sole superpower in a unipolar world.
There is no consensus among historians regarding the starting point of the Cold War. While most historians trace its origins to the period immediately following World War II, others argue that it began towards the end of World War I, though tensions between the Russian Empire and the British Empire and the United States date back to the middle of the 19th century. The ideological clash between communism and capitalism began in 1917, when the Soviet Union emerged from the Russian Revolution as the world's first communist state. This outcome rendered Russian–American relations a matter of major long-term concern for leaders in both countries.
Several events fueled suspicion and distrust between the United States and the Soviet Union: the Bolsheviks' challenge to capitalism (through violent overthrow of "capitalist" regimes to be replaced by communism), Russia's withdrawal from World War I in the Treaty of Brest-Litovsk with Germany, US intervention in Russia supporting the White Army in the Russian Civil War, and the US refusal to recognize the Soviet Union until 1933. Other events in the interwar period deepened this climate of mutual distrust. The Treaty of Rapallo and the German-Soviet Non-aggression Pact are two notable examples.
The Allies disagreed about how the European map should look, and how borders would be drawn, following the war. Both sides, moreover, held very dissimilar ideas regarding the establishment and maintenance of post-war security. The American concept of security assumed that, if US-style governments and markets were established as widely as possible, countries could resolve their differences peacefully, through international organizations. The Soviet model of security depended on integrity of their own borders. This reasoning was conditioned by Russia's historical experiences, given the frequency with which the country had been invaded from the West over the previous 150 years. The immense damage inflicted upon the USSR by the German invasion was unprecedented both in terms of death toll (est. 27 million) and the extent of destruction. Moscow was committed to ensuring that the new order in Europe would guarantee Soviet long-term security and sought to eliminate the chance of a hostile government reappearing along the USSR western border, by controlling the governments of these countries. Poland was a particularly thorny issue. In April 1945, both Churchill and the new American President, Harry S. Truman, protested the Soviets' decision to prop up the Lublin government, the Soviet-controlled rival to the Polish government-in-exile, whose relations with the Soviets were severed.
At the Yalta Conference in February 1945, the Allies attempted to define the framework for a post-war settlement in Europe but failed to reach a firm consensus. During April 1945, German Propaganda minister Joseph Goebbels warned for the first time that an "Iron Curtain" would fall across Europe. Following the Allied victory in May, the Soviets effectively occupied Eastern Europe, while strong US and Western allied forces remained in Western Europe. In occupied Germany, the US and the Soviet Union established zones of occupation and a loose framework for four-power control with the fading French and British. For the maintenance of world peace, the Allies set up the United Nations, but the enforcement capacity of its Security Council was effectively paralyzed by the superpowers' use of the veto. Indeed, the UN was essentially converted into a forum for exchanging polemical rhetoric, and the Soviets regarded it almost exclusively as a propaganda tribune.
British Prime Minister Winston Churchill was concerned that given the enormous size of Soviet forces deployed in Europe at the end of the war, and the perception that Soviet leader Joseph Stalin was unreliable, there existed a Soviet threat to Western Europe. In April-May 1945, the British War Cabinet's Joint Planning Staff Committee developed Operation Unthinkable, a plan "to impose upon Russia the will of the United States and the British Empire". The plan, however, was rejected by the British Chiefs of Staff Committee as militarily unfeasible.
At the Potsdam Conference, starting in late July, serious differences emerged over the future development of Germany and Eastern Europe. Moreover, the participants' mounting antipathy and bellicose language served to confirm their suspicions about each other's hostile intentions and entrench their positions. At this conference Truman informed Stalin that the United States possessed a powerful new weapon. Stalin was aware that the Americans were working on the atomic bomb and, given that the Soviets' own rival program was in place, he reacted to the news calmly. The Soviet leader said he was pleased by the news and expressed the hope that the weapon would be used against Japan. One week after the end of the Potsdam Conference, the US bombed Hiroshima and Nagasaki. Shortly after the attacks, Stalin protested to US officials when Truman offered the Soviets little real influence in occupied Japan.
In February 1946, George F. Kennan's "Long Telegram" from Moscow helped to articulate the US government's increasingly hard line against the Soviets, and became the basis for US strategy toward the Soviet Union for the duration of the Cold War. That 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 capital building up military capability "to prepare the conditions for winning world supremacy in a new war". On September 6, 1946, James F. Byrnes delivered a speech in Germany repudiating the Morgenthau Plan (a proposal to partition and deindustrialize post-war Germany) and warning the Soviets that the US intended to maintain a military presence in Europe indefinitely. As Byrnes admitted a month later, "The nub of our program was to win the German people [...] it was a battle between us and Russia over minds [...] A few weeks after the release of this "Long Telegram", former British Prime Minister Winston Churchill delivered his famous "Iron Curtain" speech in Fulton, Missouri. The speech called for an Anglo-American alliance against the Soviets, whom he accused of establishing an "iron curtain" from "Stettin in the Baltic to Trieste in the Adriatic".
The USSR was setting up puppet communist regimes in Bulgaria, Czechoslovakia, Hungary, Poland, Romania, and East Germany, as the Red Army maintained a military presence in most of these countries. In February 1947, the British government announced that it could no longer afford to finance the Greek monarchical military regime in its civil war against communist-led insurgents. The American government's response to this announcement was the adoption of "containment", whose goal was to stop the spread of communism. Truman gave a speech to unveil the "Truman Doctrine", which framed the conflict as a contest between "free" peoples and "totalitarian" regimes. Even though the insurgents were helped by Josip Broz Tito's Yugoslavia, US policymakers accused the Soviet Union of conspiring against the Greek royalists in an effort to "expand" Soviet influence.
For US policymakers, threats to Europe's balance of power were not necessarily military ones, but political and economic challenges. In June, the Truman Doctrine was complemented by the Marshall Plan, a pledge of economic assistance aimed at rebuilding the Western political-economic system and countering perceived threats to Europe's balance of power; such threats included attempts by communist parties to seize power through free elections or popular revolutions, in countries like France or Italy.
Stalin saw the Marshall Plan as a significant threat to Soviet control of Eastern Europe. He believed that economic integration with the West would allow Eastern Bloc countries to escape Soviet guidance, 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 western Europe, became known as the Molotov Plan, and later, the COMECON. Stalin was also fearful of a reconstituted Germany, as his vision of a post-war Germany did not include the ability to rearm, or be any kind of a threat to the Soviet Union.
In 1948, in retaliation for Western efforts to re-industrialize and rebuild the German economy, Stalin built blockades which prevented Western materials and supplies from arriving in West Berlin. This move, known as the Berlin Blockade, precipitated one of the first major crises of the Cold War. Both sides directed propaganda against the other, with the Soviets mounting a public relations campaign against the US policy change, and the US accidentally creating "Operation Little Vittles", which supplied candy to German children. The Berlin Blockade ended peacefully, with Stalin backing down and allowing the resumption of normal shipments to West Berlin.
In July, Truman rescinded the punitive Morgenthau plan (part of an agreement with the Soviet Union regarding post-war Germany), which had specifically directed US occupation forces in Germany not to assist in Germany's economic rehabilitation efforts. It was replaced by a new directive which stressed instead that European prosperity was contingent upon German economic recovery.
In September, the Soviets created Cominform, whose purpose was to enforce orthodoxy within the international communist movement and tighten political control over Soviet satellites through coordination of communist parties in the Eastern Bloc. Cominform faced an embarrassing setback the following June, when the Tito-Stalin split obliged them to expel Yugoslavia, which remained Communist but adopted a neutral stance in the Cold War.
As part of Soviet domination of Eastern Europe, the NKVD, led by Lavrentiy Beria, supervised the establishment of Soviet-style systems of secret police in the Eastern European states, which were supposed to crush anti-communist resistance. When the slightest stirrings of independence emerged among East European satellites, Stalin's strategy was to deal with those responsible in the same manner he had handled his prewar rivals within the Soviet Union: they were removed from power, put on trial, imprisoned, and in several instances, executed.
The US formally allied itself to the Western European states in the North Atlantic Treaty of April 1949, establishing the North Atlantic Treaty Organization (NATO). That August, Stalin ordered the detonation of the first Soviet atomic device.
Additionally, the US spearheaded the establishment of West Germany from the three Western zones of occupation in May 1949. To counter this Western reorganisation of Germany, the Soviet Union proclaimed its zone of occupation in Germany the "German Democratic Republic" that October. In the early 1950s, the US worked for the rearmament of West Germany and, in 1955, its full membership to NATO. In May 1953, Lavrentiy Beria, appointed First Deputy Prime Minister of the Soviet Union, made an unsuccessful proposal to allow the reunification of a neutral Germany to prevent West Germany's incorporation into NATO.
A major propaganda effort begun in 1949 was Radio Free Europe/Radio Liberty, which was dedicated to bringing about the peaceful demise of the Communist system and the governments of what were known as the satellite nations (Poland, Czechoslovakia, Hungary, Romania, and Bulgaria). Radio Free Europe attempted to fulfill these goals by serving as a surrogate home radio station, an alternative to the controlled and party-dominated domestic press. RFE was a product of some of the most prominent architects of America's early Cold War strategy, especially those who believed that the Cold War would eventually be fought by political rather than military means, such as George F. Kennan. American policymakers such as Kennan and John Foster Dulles acknowledged that the Cold War was in its essence a war of ideas. The United States, acting through the CIA, funded a long list of projects to counter the Communist appeal among intellectuals in Europe and the developing world.
US officials moved thereafter to expand "containment" into Asia, Africa, and Latin America, in order to counter revolutionary nationalist movements, often led by Communist parties financed by the USSR, fighting against the restoration of Europe's colonial empires in South-East Asia. In the early 1950s, the US formalized a series of alliances with Japan, Australia, New Zealand, Thailand and the Philippines (notably ANZUS and SEATO), thereby guaranteeing the United States a number of long-term military bases.
One of the more significant impacts of containment was the outbreak of the Korean War. As noted, the US and the Soviet Union had been fighting proxy wars, on a small scale, and without their respective troops; but to Stalin's surprise, Truman committed US forces to drive back the North Koreans, who had invaded South Korea; this action was backed by the UN Security Council only because the Soviets were then boycotting meetings to protest the fact that Taiwan and not Communist China held a permanent seat there.
Among other effects, the Korean War galvanised NATO to develop a military structure, as all communist countries were suspected of acting together. Public opinion in countries such as Great Britain, usual allies of the US, was divided for and against the war. British Attorney General Sir Hartley Shawcross repudiated the sentiment of those opposed when he said: Even though the Chinese and North Koreans were exhausted by the war and were prepared to end it by late 1952, Stalin insisted that they continue fighting, and a cease-fire was approved only in July 1953, after Stalin's death.
On November 18, 1956, while addressing Western ambassadors at a reception at the Polish embassy in Moscow, Khrushchev used his famous "Whether you like it or not, history is on our side. We will bury you" expression, shocking everyone present. However, he had not been talking about nuclear war, he later claimed, but rather about the historically determined victory of communism over capitalism. He then declared in 1961 that even if the USSR might indeed be behind the West, within a decade its housing shortage would disappear, consumer goods would be abundant, its population would be "materially provided for", and within two decades, the Soviet Union "would rise to such a great height that, by comparison, the main capitalist countries will remain far below and well behind".
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, Eisenhower curtailed Soviet threats to intervene in the Middle East during the 1956 Suez Crisis.
There was a slight relaxation of tensions after Stalin's death in 1953, but the situation in Europe remained an uneasy armed truce. US troops seemed stationed indefinitely in West Germany and Soviet forces seemed indefinitely stationed throughout Eastern Europe. To counter West German rearmament and admission into NATO, the Soviets established a formal alliance with the Eastern European Communist states called the Warsaw Treaty Organization or Warsaw Pact in 1955; this was more a political than a defence measure, as the USSR already had a network of mutual assistance treaties with all its allies in Eastern Europe by the time NATO was set up in 1949. In 1956, the status quo was briefly threatened in Hungary, when the Soviets invaded rather than allow the Hungarians to move out of their orbit, which started after Khrushchev arranged the removal from power of Hungary's Stalinist leader, Mátyás Rákosi. Berlin remained divided and contested.
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. However, Khrushchev rejected Stalin's belief in the inevitability of war, and declared his new goal was to be "peaceful coexistence". This formulation modified the Stalin-era Soviet stance, where international class struggle meant the two opposing camps were on an inevitable collision course where Communism would triumph through global war; now, peace would allow capitalism to collapse on its own, as well as giving the Soviets time to boost their military capabilities. Only with Gorbachev's "new thinking" was this vision relaxed and peaceful coexistence seen as an end in itself rather than a form of class struggle. US pronouncements concentrated on American strength abroad and the success of liberal capitalism. However, by the late 1960s, the "battle for men's minds" between two systems of social organization that Kennedy spoke of in 1961 was largely over, with tensions henceforth based primarily on clashing geopolitical objectives rather than ideology.
During November 1958, Khrushchev made an unsuccessful attempt to turn all of Berlin into an independent, demilitarized "free city", giving the United States, Great Britain, and France a six-month ultimatum to withdraw their troops from the sectors they still occupied in West Berlin, or he would transfer control of Western access rights to the East Germans. Khrushchev earlier explained to Mao, using a startling anatomical metaphor, 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.
More broadly, one hallmark of the 1950s was the beginning of European integration–a fundamental by-product of the Cold War that Truman and Eisenhower promoted politically, economically, and militarily, but which later administrations viewed ambivalently, fearful that an independent Europe would launch a separate détente with the Soviet Union, which would use this to exacerbate Western disunity.
Nationalist movements in some countries and regions, notably Guatemala, Iran, the Philippines, and Indochina were often allied with communist groups—or at least were perceived in the West to be allied with communists. In this context, the US and the Soviet Union increasingly competed for influence by proxy in the Third World as decolonization gained momentum in the 1950s and early 1960s; additionally, the Soviets saw continuing losses by imperial powers as presaging the eventual victory of their ideology. The US government utilized the CIA in order to remove a string of unfriendly Third World governments and to support others. The US used the CIA to overthrow governments suspected by Washington of turning pro-Soviet, including Iran's first democratically elected government under Prime Minister Mohammed Mossadegh in 1953 (see 1953 Iranian coup d'état) and Guatemala's democratically elected president Jacobo Arbenz Guzmán in 1954 (see 1954 Guatemalan coup d'état). Between 1954 and 1961, the US sent economic aid and military advisors to stem the collapse of South Vietnam's pro-Western regime. Both sides used propaganda to advance their cause: the United States Information Agency was set up to create support for US foreign policy, aided by its radio division, Voice of America; the BBC did its part too. The CIA spread covert propaganda against US-hostile governments (including Eastern Bloc ones), also providing funds to establish Radio Free Europe, which was frequently jammed. The Chinese and the Soviets waged an intra-Communist propaganda war after their split. Soviet propaganda used Marxist philosophy to attack capitalism, claiming labor exploitation and war-mongering imperialism were inherent in the system.
Many emerging nations of Asia, Africa, and Latin America rejected the pressure to choose sides in the East-West competition. In 1955, at the Bandung Conference in Indonesia dozens of Third World governments resolved to stay out of the Cold War. The consensus reached at Bandung culminated with the creation of the Non-Aligned Movement in 1961. Meanwhile, Khrushchev broadened Moscow's policy to establish ties with India and other key neutral states. Independence movements in the Third World transformed the postwar order into a more pluralistic world of decolonized African and Middle Eastern nations and of rising nationalism in Asia and Latin America.
On the nuclear weapons front, the US and the USSR pursued nuclear rearmament and developed long-range weapons with which they could strike the territory of the other. In August 1957, the Soviets successfully launched the world's first intercontinental ballistic missile (ICBM) and, in October, launched the first earth satellite, Sputnik. The launch of Sputnik inaugurated the Space Race. However, the period after 1956 was marked by serious setbacks for the Soviet Union, most notably the breakdown of the Sino-Soviet alliance. Mao had defended Stalin when Khrushchev attacked him in 1956, and treated the new Soviet leader as a superficial upstart, accusing him of having lost his revolutionary edge. After this, Khrushchev made many desperate attempts to reconstitute the Sino-Soviet alliance, but Mao considered it useless and denied any proposal. Further on, the Soviets focused on a bitter rivalry with Mao's China for leadership of the global communist movement, and the two clashed militarily in 1969.
The Berlin Crisis of 1961 (June 4, 1961–Nov 9 1961) was the last major incident in the Cold War regarding the status of Berlin and post-World War II Germany. It was provoked by a new ultimatum issued by the Soviet Union demanding the withdrawal of allied forces from West Berlin. It culminated in the erection of the Berlin Wall, and de facto partition of Berlin.
The nuclear arms race brought the two superpowers to the brink of nuclear war. Khrushchev formed an alliance with Fidel Castro after the Cuban Revolution in 1959. In 1962, President John F. Kennedy responded to the installation of nuclear missiles in Cuba with a naval blockade. The Cuban Missile Crisis brought the world closer to nuclear war than ever before in the history of the Cold War. It also showed that neither superpower was prepared to use nuclear weapons for fear of the other's retaliation, and thus of mutually assured destruction. The aftermath of the crisis led to the first efforts at nuclear disarmament and improving relations, though the Cold War's first arms control agreement, the Antarctic Treaty, had come into force in 1961.
In 1964, Khrushchev's Kremlin colleagues managed to oust him, but allowed him a peaceful retirement. Accused of rudeness and incompetence, he was also credited with ruining Soviet agriculture and bringing the world to the brink of nuclear war. Khrushchev had become an international embarrassment when he authorised construction of the Berlin Wall, a public humiliation for Marxism-Leninism.
In the course of the 1960s and '70s, both the US and the Soviet Union 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 postwar period, Western Europe and Japan rapidly recovered from the destruction of World War II and sustained strong economic growth through the 1950s and '60s, increasing their strength compared to the United States. As a result of the 1973 oil crisis, combined with the growing influence of Third World alignments such as the Organization of Petroleum Exporting Countries (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. Moscow, meanwhile, 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 Alexei Kosygin and Leonid Brezhnev embraced the notion of détente.
Nevertheless, both superpowers resolved to reinforce their global leadership. Both the United States and the Soviet Union struggled to stave off challenges to their leadership in their own regions. President Lyndon B. Johnson landed 22,000 troops in the Dominican Republic in Operation Power Pack, citing the threat of the emergence of a Cuban-style revolution in Latin America. Western Europe remained dependent on the US for its defence, a status most vociferously contested by France's Charles de Gaulle, who in 1966 withdrew from NATO's military structures and expelled NATO troops from French soil. In 1968, the Soviets together with most of their Warsaw pact allies, invaded Czechoslovakia, and then crushed the Prague Spring reform movement, which had threatened to take the country out of the Warsaw Pact. The invasion sparked intense protests from Yugoslavia, Romania and China, and from Western European communist parties.
On November 13, 1968, during a speech at the Fifth Congress of the Polish United Workers' Party, Brezhnev outlined the Brezhnev Doctrine, in which he claimed the right to violate the sovereignty of any country attempting to replace Marxism-Leninism with capitalism. During the speech, Brezhnev stated: The reasons for adopting such a doctrine had to do with the failures of Marxism-Leninism in states like Poland, Hungary and East Germany, which were facing a declining standard of living, in contrast with the prosperity of West Germany and the rest of Western Europe.
The US continued to spend heavily on supporting friendly Third World regimes in Asia. Conflicts in peripheral regions and client states—most prominently in Vietnam—continued. Johnson stationed 575,000 troops in Southeast Asia to defeat the National Front for the Liberation of South Vietnam (NLF) and their North Vietnamese allies in the Vietnam War, but his costly policy weakened the US economy and, by 1975, ultimately culminated in what most of the world saw as a humiliating defeat of the world's more powerful superpower at the hands of one of the world's poorest nations. Additionally, Operation Condor, employed by South American dictators to suppress leftist dissent, was backed by the US, which (sometimes accurately) perceived Soviet or Cuban support behind these opposition movements. Brezhnev, meanwhile, faced far more daunting challenges in reviving the Soviet economy, which was declining in part because of heavy military expenditures. Moreover, the Middle East continued to be a source of contention. Egypt, which received the bulk of its arms and economic assistance from the USSR, was a troublesome client, with a reluctant Soviet Union feeling obliged to assist in both the Six-Day War (with advisers and technicians) and the War of Attrition (with pilots and aircraft) against US ally Israel; Syria and Iraq later received increased assistance as well as (indirectly) the PLO. During the Yom Kippur War, rumors of imminent Soviet intervention on the Egyptians' behalf brought about a massive US mobilization that threatened to wreck détente; this escalation, the USSR's first in a regional conflict central to US interests, inaugurated a new and more turbulent stage of Third World military activism and made use of the new Soviet strategic parity.
Although indirect conflict between Cold War powers continued through the late 1960s and early 1970s, tensions began to ease as the period of détente began. The Chinese had sought improved relations with the US in order to gain advantage over the Soviets. In February 1972, Richard Nixon traveled to Beijing and met with Mao Zedong and Chou En-Lai. Nixon and Henry Kissinger then announced a stunning rapprochement with Mao's China. A desire by the USSR to contain China fear of conflict on both its European and Asian fronts, and a renewed sense of encirclement by adversaries was one factor leading to the Soviet-US détente. Its other two principal causes were the USSR's having achieved rough nuclear parity with the US and the serious weakening the Vietnam War was causing the United States (a reduction of influence in the Third World and a cooling of relations with Western Europe).
Later, in May, Nixon and Kissinger met with Soviet leaders in Moscow, and announced the first of the Strategic Arms Limitation Talks, aimed at limiting the development of costly antiballistic missiles and offensive nuclear missiles. Between 1972 and 1974, the two sides also agreed to strengthen their economic ties. Meanwhile, these developments coincided with the "Ostpolitik" of West German Chancellor Willy Brandt. 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 KGB, led by Yuri Andropov, continued to persecute distinguished Soviet personalities such as Aleksander Solzhenitsyn and Andrei Sakharov, who were criticising the Soviet leadership in harsh terms. Indirect conflict between the superpowers continued through this period of détente in the Third World, particularly during political crises in the Middle East, Chile, Ethiopia and Angola. While President Jimmy Carter tried to place another limit on the arms race with a SALT II agreement in 1979, his efforts were undercut by the other events that year, including the Iranian Revolution and the Nicaraguan Revolution, which both ousted pro-US regimes, and his retaliation against Soviet intervention in Afghanistan in December.
The term second Cold War has been used by some historians to refer to the period of intensive reawakening of Cold War tensions and conflicts in the early 1980s. Tensions greatly increased between the major powers with both sides becoming more militaristic.
During December 1979, about 75,000 Soviet troops invaded Afghanistan in order to support the Marxist government formed by ex-Prime-minister Nur Muhammad Taraki, assassinated that September by one of his party rivals. As a result, US President Jimmy Carter withdrew the SALT II treaty from the Senate, imposed embargoes on grain and technology shipments to the USSR, demanded a significant increase in military spending and further announced that the United States would boycott the 1980 Moscow Summer Olympics. He described the Soviet intervention in Afghanistan as "the most serious threat to the peace since the Second World War".
In 1980, Ronald Reagan defeated Jimmy Carter in the US presidential election, vowing to increase military spending and confront the Soviets everywhere. Both Reagan and Britain's new prime minister, Margaret Thatcher, denounced the Soviet Union and its ideology in terms that rivaled those of the worst days of the Cold War in the late 1940s, with Reagan vowing to leave the "evil empire" on the "ash heap of history". 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 focused on the Solidarity movement that galvanized opposition and may have led to his attempted assassination two years later. Reagan also imposed economic sanctions on Poland to protest the suppression of the opposition Solidarity movement. In response, Mikhail Suslov, the Kremlin's top ideologist, advised the Soviet leaders not to intervene if Poland fell under the control of Solidarity, as it may have led to heavy economic sanctions representing a catastrophe for the Soviet economy.
With the background of a buildup in tensions between the Soviet Union and the United States, and the deployment of Soviet SS-20 ballistic missiles targeting Western Europe, NATO decided, under the impetus of the Carter presidency, to deploy Pershing II and cruise missiles in Europe, primarily West Germany. This deployment would have placed missiles just 10 minutes' striking distance from Moscow. Yet support for the deployment was wavering and many doubted whether the push for deployment could be sustained. But on September 1, 1983, the Soviet Union shot down Korean Air Lines Flight 007, a Boeing 747 with 269 people aboard when it violated Soviet airspace just past the west coast of Sakhalin Island—an act which Reagan characterized as a "massacre". This act galvanized support for the deployment, which Reagan oversaw and stood in place until the later accords between Reagan and Mikhail Gorbachev. The Able Archer 83 exercise in November 1983, a realistic simulation of a coordinated NATO nuclear release, was the most dangerous moment since the Cuban Missile Crisis, as Soviet leadership keeping a close watch on it, considered a nuclear attack imminent.
Moscow had built up a military that consumed as much as 25 percent of the Soviet Union's 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 saw at least a decade of economic stagnation during the late Brezhnev years. Soviet investment in the defence sector was not driven by military necessity, but in large part by the interests of massive party and state bureaucracies 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.
By the early 1980s, the USSR had built up a military arsenal and army surpassing that of the United States. Previously, the US had relied on the qualitative superiority of its weapons, but the gap had been narrowed. Ronald Reagan began massively building up the United States military not long after taking office. This led to the largest peacetime defence buildup in United States history. Tensions continued intensifying in the early 1980s when Reagan revived the B-1 bomber program that was canceled by the Carter administration, produced MX "Peacekeeper" missiles, installed US cruise missiles in Europe, and announced his experimental Strategic Defence Initiative, dubbed "Star Wars" by the media, a defence program to shoot down missiles in mid-flight.
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, Reagan persuaded Saudi Arabia to increase 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. The decrease in oil prices and large military expenditures gradually brought the Soviet economy to a stagnant state at this time.
US 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 US, his backing of the Contra rebels was mired in controversy.
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 many countries (especially the US), 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. ... It may be that the thermodynamic law of entropy has ... caught up with the Soviet system, which now seems to expend more energy on simply maintaining its equilibrium than on improving itself. We could be seeing a period of foreign movement at a time of internal decay". The Soviets were not helped by their aged and sclerotic leadership either: Brezhnev, virtually incapacitated in his last years, was succeeded by Andropov and Chernenko, neither of whom lasted long. After Chernenko's death, Reagan was asked why he had not negotiated with Soviet leaders. Reagan quipped, "They keep dying on me".
By the time Mikhail Gorbachev became General Secretary of the Communist Party of the Soviet Union in 1985, the Soviet economy was stagnant and faced a sharp fall in foreign currency earnings as a result of weak oil prices in the 1980s. These issues prompted Gorbachev to investigate measures to revive the ailing state. An inneffectual start led to the conclusion that deeper structural changes were necessary and in June 1987 Gorbachev announced an agenda of economic reform, called perestroika, or restructuring. Perestroika relaxed the production quota system, allowed private ownership of businesses and paved the way for foreign investment. These measures were intended to redirect the country's resources from costly Cold War military commitments to more profitable areas in the civilian sector. Despite initial scepticism in the West, the new Soviet leader proved to be committed to reversing the Soviet Union's deteriorating economic condition instead of continuing the arms race with the West. Gorbachev simultaneously introduced glasnost, or openness, which increased freedom of the press and the transparency of state institutions. Glasnost was intended to reduce the corruption at the top of the Communist Party and moderate the abuse of power in the Central Committee. Glasnost also enabled increased contact between Soviet citizens and the western world, particularly with the United States, contributing to the accelerating détente between the two nations.
In response to the Kremlin's military and political concessions, Reagan agreed to renew talks on economic issues and the scaling-back of the arms race. The first was held in November 1985 in Geneva, Switzerland. At one stage the two men, accompanied only by a translator, agreed in principle to reduce each country's nuclear arsenal by 50 percent. The second summit was held the following year in Reykjavík, Iceland. Talks went well until the focus shifted to Reagan's proposed Strategic Defence Initiative, which Gorbachev wanted eliminated: Reagan refused. The negotiations failed, but the third summit in 1987 led to a breakthrough with the signing of the Intermediate Range Nuclear Forces Treaty (INF). The INF treaty eliminated all nuclear-armed, ground-launched ballistic and cruise missiles with ranges between 500 and 5,500 kilometers (300 to 3,400 miles) and their infrastructure. East–West tensions rapidly subsided through the mid-to-late 1980s, culminating with the final summit in Moscow in 1989, when 30 July Gorbachev and George H. W. Bush signed the START I arms control treaty. During the following year it became apparent to the Soviets that oil and gas subsidies, along with the cost of maintaining massive troops levels, represented a substantial economic drain. In addition, the security advantage of a buffer zone was recognised as irrelevant and the Soviets officially declared that they would no longer intervene in the affairs of allied states in Eastern Europe. In 1989, Soviet forces withdrew from Afghanistan and by 1990 Gorbachev consented to German reunification, the only alternative being a Tiananmen scenario. When the Berlin Wall came down, Gorbachev's "Common European Home" concept began to take shape.
By 1989, the Soviet alliance system was on the brink of collapse, and, deprived of Soviet military support, the Communist leaders of the Warsaw Pact states were losing power. In the USSR itself, glasnost weakened the bonds that held the Soviet Union together and by February 1990, with the dissolution of the USSR looming, the Communist Party was forced to surrender its 73-year-old monopoly on state power.
At the same time freedom of press and dissent allowed by glasnost and the festering "nationalities question" increasingly led the Union's component republics to declare their autonomy from Moscow, with the Baltic states withdrawing from the Union entirely. The 1989 revolutionary wave that swept across Central and Eastern Europe overthrow the Soviet-style communist states, such as Poland, Hungary, Czechoslovakia and Bulgaria, Romania being the only Eastern-bloc country to overthrow its communist regime violently and execute its head of state. Gorbachev's permissive attitude toward Eastern Europe did not initially extend to Soviet territory; even Bush, who strove to maintain friendly relations, condemned the January 1991 killings in Latvia and Lithuania, privately warning that economic ties would be frozen if the violence continued. The USSR was fatally weakened by a failed coup and as a growing number of Soviet republics, particularly Russia, threatened to secede the USSR was declared officially dissolved on December 25, 1991.
Two years earlier, in December 1989, Gorbachev and Reagan's successor, George H. W. Bush, had declared the Cold War over at the Malta Summit; a year later, the two former rivals were partners in the Gulf War against longtime Soviet ally Iraq.
Created on 21 December 1991, the Commonwealth of Independent States is viewed as a successor entity to the Soviet Union but according to Russia's leaders its purpose was to "allow a civilized divorce" between the Soviet Republics and is comparable to a loose confederation.
Following the Cold War, Russia cut military spendings dramatically, but the adjustment was wrenching, as the military-industrial sector had previously employed one of every five Soviet adults and its dismantling left millions throughout the former Soviet Union unemployed. After Russia embarked on capitalist economic reforms in the 1990s it suffered a financial crisis and a recession more severe than the US and Germany had experienced in the Great Depression. Russian living standards have worsened overall in the post-Cold War years, although the economy has resumed growth since 1999.
The legacy of the Cold War continues to influence world affairs. The Cold War defined the political role of the United States in the post-World War II world: by 1989 the US held military alliances with 50 countries and had 1.5 million troops posted abroad in 117 countries. The Cold War also institutionalized a global commitment to huge, permanent peacetime military-industrial complexes and large-scale military funding of science.
Most of the proxy wars and subsidizing local conflicts ended along with the Cold War; the occurrence of interstate wars, ethnic wars, revolutionary wars, as well as refugee and displaced persons crises has declined sharply in recent years. However, the legacy of Cold War conflict is not always easily erased, as many of the economic and social tensions that were exploited to fuel Cold War competition in parts of the Third World remain acute. The breakdown of state control in a number of areas formerly ruled by Communist governments has produced new civil and ethnic conflicts, particularly in the former Yugoslavia. In Eastern Europe, the end of the Cold War has ushered in an era of economic growth and a large increase in the number of liberal democracies, while in other countries such as Afghanistan independence was accompanied by state failure.
While the explanations of the origins of the conflict in academic discussions are complex and diverse, several general schools of thought on the subject can be identified. Historians commonly speak of three differing approaches to the study of the Cold War: "orthodox" accounts, "revisionism", and "post-revisionism".
This "orthodox" accounts place the responsibility for the Cold War on the Soviet Union and its expansion into Eastern Europe. "Revisionist" writers placed more responsibility for the breakdown of postwar peace on the United States, citing a range of U.S. efforts to isolate and confront the Soviet Union well before the end of World War II. "Post-revisionists" saw the events in the Cold War as more nuanced, and attempted to be more balanced in determining what occurred during the Cold War.
Much of the historiography on the Cold War weaves together two or even all three of these broad categories.