President Harry S. Truman confronted unprecedented challenges in international affairs during his nearly eight years in office. Truman guided the United States through the end of World War II, the beginning of the Cold War between the United States and the Soviet Union, and the dawning of the atomic age. Truman intervened with American troops in the conflict between North Korea and South Korea and he supported the creation of the state of Israel in the Middle East. In sum, Truman's foreign policy established some of the basic principles and commitments that marked American foreign policy for the remainder of the twentieth century.

Truman's National Security Team

Truman inherited Roosevelt's national security team, though he would transform it—in terms of both personnel and organization—during the course of his presidency. At the State Department, Truman replaced FDR's last secretary of state, Edward Stettinius, with former senator, Supreme Court justice, and war mobilization director James F. Byrnes. Byrnes handled the opening rounds of negotiations at the postwar conferences of allied foreign ministers, but he proved problematic for the President. Truman replaced him in 1947 with Gen. George C. Marshall, Army chief of staff during the war, who had attempted to mediate the Chinese civil war during 1946. Marshall, in turn, was succeeded by Dean G. Acheson, a former undersecretary of state, in 1949. Marshall and Acheson proved inspired leaders and sometimes brilliant architects of United States foreign policy.

Truman also reorganized the nation's military and national security apparatus with passage of the National Security Act in 1947. The legislation had three main purposes. It unified the Army, Navy, and Air Force under a National Military Establishment (NME) headed by a civilian Secretary of Defense. Two years later, the NME was renamed the Department of Defense and made an executive department. The National Security Act also created the Central Intelligence Agency, the leading arm of the nation's intelligence network. Finally, the Act established the National Security Council (NSC) to advise the President on issues related primarily to American foreign policy. While underdeveloped and undernourished during its first years of existence, the NSC grew in prestige and power due to U.S. involvement in the Korean War. Over the coming decades, the NSC became a significant instrument of American foreign policy.

Entering the Atomic Age

When Truman ascended to the presidency on April 12, 1945, World War II in Europe was almost over; within a month, Hitler committed suicide and Germany surrendered. In the Pacific, however, the end of the war with Japan seemed farther away. As Truman took office, military planners anticipated that total victory would require an Allied invasion of Japan. The invasion would likely prolong the war for at least another year and cost, by one estimate, over 200,000 American casualties.

Truman knew that another option might exist. The top-secret Manhattan Project was at work on an atomic bomb, a device that one of the President's advisers described "as the most terrible weapon ever known in human history." While attending the Potsdam summit in July, Truman learned that a test of the bomb had been successful. The possibility of bringing the war to an earlier conclusion was exceedingly attractive; the added heft this new weapon might give to perceptions of U.S. power, while hardly determinative, also weighed on the President's mind. With figures for a full-scale invasion of the Japanese home islands mounting and Japanese leaders offering few concrete hints of agreeing to the President's terms for unconditional surrender, Truman endorsed the use of the bomb against Japan.

On the morning of August 6, 1945, the B-29 bomber Enola Gay dropped an atomic bomb on Hiroshima, Japan. Estimates of the casualties are notoriously slippery, but upwards of 100,000 people, perhaps—mostly civilians—perished instantly. Two days later, hearing no word from the Japanese government (which was in deep negotiations about whether to surrender), Truman let the U.S. military proceed with its plans to drop a second atomic bomb. On August 9, that weapon hit Nagasaki, Japan. The Japanese agreed to surrender on August 14 and then did so, more formally, on September 2. World War II was over.

Problems with the Soviet Union

Even before the end of World War II, tensions between the Soviet Union and the United States began to mount as both nations looked to shape the post-war international order in line with their interests. One of the most important flashpoints was Poland. At the Yalta conference in February 1945, the Soviet Union agreed in general terms to the establishment of freely elected governments in recently liberated areas of eastern Europe. Never fulfilling this promise, it established a Polish Communist-dominated puppet government in the spring of 1945 as the first of what would later become its eastern European satellites.

Truman hoped that the United States and the U.S.S.R. could maintain amicable relations, though he realized that conflicts would surely arise between the globe's most powerful nations. He believed that tough-minded negotiation and the occasional compromise would allow the United States nevertheless to achieve a modus vivendi favorable to American interests. A few of Truman's advisers dissented from even this guarded approach. Citing the situation in Poland, they warned that the Soviets would try to dominate as much of Europe as possible.

At Potsdam in July 1945, Truman met face-to-face with Soviet leader Josef Stalin and British prime minister Winston Churchill. The conference moved slowly and settled little. Stalin re-iterated his earlier pledge to enter the war in the Pacific against Japan—an offer Truman readily accepted—but American efforts to lessen Soviet influence over eastern Europe went nowhere. Nonetheless, as the conference came to an end, Truman wrote to Bess, "I like Stalin . . . He is straightforward. Knows what he wants and will compromise when he can't get it."In the coming months and years, Truman would change his opinion. Potsdam had been a personal success for Truman—he appeared to get along with his fellow heads of state—but the inability to settle outstanding issues, such as the future of Germany, the boundaries of postwar Poland, and the nature of wartime reparations hinted at serious underlying differences between the two nations. Secretary of State Byrnes tried in vain to work with the Soviets through the last months of 1945 and into early 1946, though without much success. At the same time, the Soviets tightened their control over eastern Europe and attempted to extend their influence into Turkey and Iran. The United States blunted Soviet intentions in those two nations through diplomacy and a show of military strength. Stalin heightened tensions with a fiery speech in February 1946, predicting a coming clash with capitalism.

The Early Cold War

Each of these developments frustrated and worried American leaders. Truman told Byrnes in January 1946, "I'm tired babying the Soviets." Others agreed. In February, George F. Kennan, the temporary head of the American embassy in Moscow, sent his assessment of Soviet foreign policy to Washington in what became known as the "long telegram." Kennan argued that the Soviets, motivated by a combination of Marxist-Leninist ideology and traditional Russian security concerns, were bent on expansion and were irrevocably opposed to the United States and the West, as well as to capitalism and democracy. He urged American leaders to confront and contain the Soviet threat. Two weeks later, former British prime minister Winston Churchill, speaking in Fulton, Missouri, declared that the Soviets were bringing an "iron curtain" down across Europe—and that the United States and Britain needed to vigorously oppose Soviet expansionism. Kennan's analysis gave American officials a framework for understanding the Soviet challenge, Churchill's formulation brought the threat home to the public at-large.

Relations between the two nations continued to worsen in 1946. Britain received a $3.75 billion loan from the U.S. government to help it rebuild. In Stuttgart, Germany, Secretary of State Byrnes committed the United States to the reconstruction of that country both economically and politically—and promised to keep troops there as long as necessary. These two decisions hinted at an emerging worldview among government policymakers: American interests required more active protection from Soviet encroachment. It came as little surprise, then, when Truman dismissed Secretary of Commerce Henry Wallace in September 1946 after Wallace gave a speech repudiating the administration's anti-Soviet foreign policy.

America sharpened its approach toward the U.S.S.R. in 1947. The President and his advisers grew more concerned that west European nations, still reeling from the devastation wrought by World War II, might elect indigenous Communist governments that would orient their nations—politically, economically, and militarily—toward the Soviet Union. Moreover, after the British government told American officials that it could no longer afford to serve as the watchdog of the eastern Mediterranean, Truman announced in March 1947 what came to be known as the Truman Doctrine. He pledged U.S. support for the pro-Western governments of Greece and Turkey—and, by extension, any similarly threatened government—arguing that the United States had a duty to support "free peoples who are resisting attempted subjugation by armed minorities or by outside pressures." In the summer of 1947, Secretary of State George Marshall announced a multi-billion dollar aid program for Europe, which became known as the Marshall Plan, that he hoped would encourage both political and economic stability and reduce the attraction of communism to Europe's suffering populations.

In 1948, the final pieces of the Cold War chessboard began to fall into place. In February, Soviet-backed communists seized control of Czechoslovakia, the last remaining independent democracy in Eastern Europe. In March, the Truman administration won congressional approval of the Marshall Plan. And throughout the spring and summer, the United States, England, and France—each occupying a zone of Germany—accelerated the process of merging those regions into a separate country that, by 1949, would become West Germany. The Soviets responded by blockading western access routes to Berlin which, while in their zone, was administered jointly by all four powers. Truman, determined not to abandon the city, ordered an airlift of food and fuel to break the blockade.

The Berlin stand-off lasted until May 1949, when the Soviets called off the blockade in return for a conference on the future of Germany. The meeting ended in failure after Stalin refused a U.S. and British offer to make the Soviet zone part of a democratic, unified Germany; the country would remain divided between West and East until October 1990. Just as important, the February 1948 Communist coup in Czechoslovakia and the Soviet-American confrontation over Berlin spurred the creation of an alliance, largely on the invitation of European statesmen, between the United States, Canada, and Western Europe—what became known as the North Atlantic Treaty Organization, or NATO—to counter Soviet power. By mid-1949, Europe was divided politically, economically, militarily, and ideologically.

That year also marked the end of the U.S. nuclear monopoly. Truman had hoped that in the wake of Hiroshima and Nagasaki, the development of atomic energy (for both peaceful and martial uses) would be placed under U.N. control. In early 1946, the Soviets rejected the U.S.-sponsored plan, which would have left the American atomic monopoly in place. Instead, the Kremlin redoubled its efforts to build a bomb which, through the aid of atomic espionage, came to fruition much more quickly than American policymakers and intelligence experts ever predicted.

Moscow's successful test of an atomic weapon in the late summer of 1949 forced the Truman administration to re-evaluate its national security strategy. Truman decided in January 1950 to authorize the development of an even more powerful weapon—the hydrogen bomb—to counter the Soviets, thus accelerating the Cold War arms race. In September, Truman approved a National Security Council document—NSC-68—that reevaluated and recast American military strategy. Among other things, NSC-68 stressed the need for a massive buildup of conventional and nuclear forces, no matter the cost. Truman greeted NSC-68, and its military and economic implications, with ambivalence, though the war in Korea, which began in the summer of 1950 and made the danger of armed challenge from the U.S.S.R. seem real and perhaps immediate, led to a more rapid implementation of the document's findings.

The United Nations

In the years after World War II, Truman worked diligently to assure that the United Nations—conceived by President Franklin D. Roosevelt as a forum in which differences between nations could be resolved before they led to war - would be a significant player in international life. For the most part, he succeeded.

The new President sent a bipartisan delegation to the United Nation's founding conference in San Francisco in mid-1945, believing it essential that both of the major American political parties endorse the organization. The major roadblock to the formation of the United Nations came from the Soviets, who were slow to join. Truman managed to secure their participation after sending special emissary Harry Hopkins to Moscow. Some Americans would later argue, however, that the price of that participation—American acquiescence to a reorganized Polish government allied with the Soviets—was too steep. Nonetheless, the San Francisco Conference adjourned in June 1945 after its participating nations, including the Soviets, signed the founding U.N. Charter.

The United Nation's most significant accomplishment during the Truman years came during the Korean War. In the wake of North Korea's invasion of South Korea, the U.N. Security Council met, officially condemned North Korea's aggression, and pledged military support to South Korea. Though the United States provided most of the U.N. troops that fought in the war alongside the South Koreans, these forces were part of a multilateral effort. The Soviet Union, a member of the Security Council, could have vetoed U.N. involvement in the war were it not for their boycott of the meeting; Moscow was protesting the U.N.'s failure to seat a representative of the newly established—and communist—People's Republic of China.

Success and Failure in Asia

In Japan, which the United States occupied at the conclusion of World War II, General Douglas MacArthur oversaw a Japanese economic recovery and political reformation. Japan's new constitution took its cues from the ideals embodied in the American constitution. With the onset of the Korean War, the Japanese economy began its slow and steady rise to prominence, peaking in the 1980s.

The United States and the Truman administration proved less successful in shaping China's political future. In the wake of World War II, civil war resumed between supporters of nationalist Chinese leader Jiang Jieshi and the forces of Communist leader Mao Zedong. Truman sent General George C. Marshall to China in 1946 in an ultimately unsuccessful attempt to mediate the conflict and form a coalition government. The administration determined privately that no amount of American aid could save Jiang, that western Europe more urgently required U.S. funding, and that the triumph of Mao's forces would not be disastrous to American interests. By August 1949, the State Department would issue a "white paper" outlining the administration's position on China and the reasons for the coming communist victory.

Two months later, on October 1, 1949, Mao declared the founding of the People's Republic of China. With Jiang's forces in full retreat to the island of Formosa, the President and his advisers confronted the firestorm in American politics touched off by the Chinese Communist victory. Republicans in Congress, including a group who wanted to reorient American foreign policy away from Europe and toward Asia, howled that the Truman administration had "lost" China. After Mao and Stalin agreed in early 1950 to a mutual defense treaty, critics of the administration's China policy redoubled their attacks. In this era of the Red Scare—Senator Joseph McCarthy leveled his infamous allegations regarding communists in the State Department in February 1950—the "loss" of China constituted a damning political charge.

The Korean War

Truman's troubles in Asia exploded on the Korean peninsula. In the wake of World War II, Korea had been partitioned at the 38th parallel, with the Soviets supporting a communist regime north of that boundary and the Americans a non-communist one in the south. On June 25, 1950, North Korea launched a surprise invasion of South Korea. The United Nations immediately condemned North Korea, while Truman and his advisers in Washington discussed the American response. Certain that the Soviet Union lay behind the invasion, they reasoned that failure to act would lead U.S. allies to question America's commitment to resist Soviet aggression. Truman resolved not to repeat the mistake of Munich, where the European powers appeased and condoned Hitler's expansionism. Scholars now know that the invasion was the brain-child of North Korean leader Kim Il-sung and that Stalin acceded to it only after making clear that the Soviets themselves would not become involved militarily and that Mao provide ground troops. Ultimately, the Soviets did provide the North Koreans with air support.

Truman ordered the American military, under the direction of General Douglas MacArthur, to intervene. The first U.S. troops did little to stop the onslaught as North Korean forces made rapid progress in their march down the peninsula. By August, the Americans were holed-up in a defensive perimeter on the southeastern tip of South Korea. MacArthur launched an audacious and risky counter-attack the following month that featured an amphibious landing behind enemy lines at Inchon on the western coast of South Korea, near the capital of Seoul.

MacArthur's gamble worked; American forces rapidly drove the North Koreans back to the border at the 38th parallel. MacArthur then received permission from the Truman administration to cross the border to secure the final defeat of North Korea and the reunification of the country. The danger, though, was obvious. The Soviet Union and China both bordered North Korea and neither wanted an American-led military force, or an American ally, on their doorsteps. In mid-October, meeting with the President at Wake Island, MacArthur told Truman that there was "very little" chance of Chinese or Soviets intervention. At the same time, however, the Chinese warned American officials though third-party governments that they would enter the war if the United States crossed the 38th parallel.

Disregarding these warnings, American forces pushed northward throughout October and into November 1950, coming to within several miles of the Chinese border. The Chinese entered the battle in late November, launching a massive counter-attack that threw the Americans back south of the 38th parallel; an American response in the spring of 1951 pushed the front north to the 38th parallel, the status quo antebellum. A brutal and bloody stalemate ensued for the next two years as peace talks moved forward in fits and starts.

American involvement in Korea brought Truman more problems than successes. After General MacArthur publicly challenged the administration's military strategy in the spring of 1951, Truman fired him. MacArthur returned home a hero, however, and Truman's popularity plummeted. Against the backdrop of McCarthyism, the failure to achieve military victory in Korea allowed Republicans to attack Truman mercilessly. Indeed, the war so badly eroded Truman's political standing that the President's slim chances of winning passage of his "Fair Deal" domestic legislation disappeared altogether.

Despite these setbacks, Truman's decision to stand and fight in Korea was a landmark event in the early years of the Cold War. Truman reassured America's European allies that the U.S. commitment to Asia would not come at Europe's expense—a commitment made more tangible in 1951 by increased American troop deployments to Europe and not Korea. The President thus guaranteed the United States to the defense of both Asia and Europe from the Soviet Union and its allies. Likewise, the Korean War locked in the high levels of defense spending and rearmament called for by NSC-68. Finally, the American effort in Korea was accompanied by a serious financial commitment to the French defense of a non-communist Indochina. In a very real sense, Korea militarized the Cold War and expanded its geographic reach.

The Creation of Israel

Between 1945 and 1948, Truman wrestled with the Jewish-Arab problem in British-controlled Palestine. Britain had searched for a solution to the conflict between Palestine's Jewish minority and Arab majority since the end of the first world war, but with little success; Arabs repeatedly rejected the British suggestion that a Jewish "national home" be created in Palestine. In February 1947, the British government, straining to uphold its other imperial commitments and with its soldiers constantly under attack by Jewish militias, announced it would shortly pass control of Palestine to the United Nations. The United Nations, in August 1947, proposed to partition Palestine into two states, one for an Arab majority and one for the Jewish minority. Jews, by and large, accepted this solution, while Arabs vigorously opposed the plan, as they had for the preceding decades. The prospect of partition ignited a savage and destructive guerilla war between Arabs and Jews in Palestine.

The question Truman faced was whether to accept the U.N. partition plan and the creation of a Jewish state. While Truman personally sympathized with Jewish aspirations for a homeland in the Middle East, the issue involved both domestic and foreign concerns. The President and his political advisers were very aware that American Jews, a major constituency in the Democratic Party, supported a state for their co-religionists in the Middle East. In an election year, Democrats could ill afford to lose the Jewish vote to Republicans. On the other hand, Truman's foreign policy advisers, especially Secretary of State Marshall, counseled strongly against American support for a Jewish state. They worried that such a course was certain to anger the Arab states in the region and might require an American military commitment. As at least one high-ranking Defense Department official argued, access to oil, not the creation of a Jewish homeland, was America's priority in the Middle East.

In November 1947, Truman ordered the American delegation at the United Nations to support the partition plan. In the following months, though, bureaucratic battles among presidential advisers over the wisdom of the plan intensified, and Truman apparently lost control of the policy-making process. He ended up endorsing a plan—by mistake, apparently—that would have established the Jewish state as a United Nations trusteeship, rather than as an autonomous entity. Truman back-tracked furiously from his remark, though without clarifying U.S. intentions. Events in Palestine forced the President's hand, however. The military triumph of Jewish nationalists over their Arab opponents in the guerilla war made it clear that the Israeli nation would soon come into being. On May 15, the United States, at Truman's direction, became the first country to recognize the state of Israel.