Although both Truman and Stalin helped increase tensions in Europe and East Asia in the years immediately following World War II, the Cold War itself was likely inevitable. The alliance that had formed between the United States and the USSR during World War II was not strong enough to overcome the past decades of suspicion and unease between the two nations. Moreover, as both leaders sought to achieve their postwar security objectives, which were often mutually exclusive, neither was willing to compromise.

The United States and the USSR had always generally disliked and distrusted each other, despite the fact that they were allies against Germany and Japan during the war. Americans had hated and feared Communism ever since it had appeared in the Bolshevik Revolution of 1917 and had refused to recognize the new Soviet government, especially after Bolshevik leaders promoted the destruction of capitalism. During World War II, Roosevelt and British prime minister Winston Churchill delayed their decision to open a second front, which would have distracted the Nazis and taken pressure off the Red Army entrenched at Stalingrad. Stalin resented this delay, just as he resented the fact that the United States and Great Britain refused to share their nuclear weapons research with the Soviet Union. After the war, Truman’s decision to give Great Britain relief loans while denying similar requests from the USSR only added to the resentment.

Another major factor contributing to the Cold War was the fact that the United States and USSR were the only two powers to escape World War II relatively unharmed. Whereas other major world powers such as Great Britain, France, Italy, and Germany lay in ruins, the Soviet Union and the United States still had manufacturing and military capabilities. The world had been a multipolar one before the war but was bipolar afterward, and this new order implicitly pitted the already distrustful and ideologically opposed United States and Soviet Union against each other.

Perhaps most important, both powers had conflicting security goals that neither wanted to concede. The USSR, which had already been invaded twice in the first half of the twentieth century, wanted to set up friendly governments throughout Eastern Europe to create a buffer between Moscow and Germany. In addition to exacting enormous war reparations, Stalin wanted to dismantle German factories to keep Germany weak and dependent. Truman, conversely, believed that rebuilding, reindustrializing, and democratizing Europe was the key to preventing another world war. With neither side willing to compromise on these conflicting ideologies and postwar plans, tension between the United States and the USSR was inevitable.

The Korean War has often been called America’s “forgotten war” because the United States made no significant territorial or political gains during the war. Despite the fact that tens of thousands of Americans died, the war both began and ended with the Korean Peninsula divided at the 38th parallel. Nevertheless, the Korean War helped define the Cold War, established a precedent for keeping peripheral wars limited, and boosted defense spending that contributed to the postwar economic boom in the United States.

Despite the loss of life, the Korean War faded from national memory, perhaps because the three-year conflict ended without any territorial or political gains. Although General Douglas MacArthur captured nearly the entire Korean Peninsula after his brilliant Inchon landing, his tactical miscalculation at the Yalu River brought China into the war and forced United Nations troops back down to the 38th parallel, where they had started. Both sides became entrenched there, each preventing the other from making any headway. As a result, neither side could claim victory when cease-fire negotiations began in 1953. The 38th parallel remained one of the “hottest” Cold War borders in the world, almost as if the war had never really ended.

The Korean War was an important conflict, however, because it set the tone for the entire Cold War. In expanding the draft and sending more than 3 million U.S. troops to Korea, Truman demonstrated to the USSR his commitment to containing Communism at almost any cost. This demonstration of massive U.S. military force in East Asia forced the Soviets to rethink postwar policy in Eastern Europe and the rest of Asia.

Truman also set a precedent during the war of avoiding the use of nuclear weapons, despite the fact that MacArthur advocated using them against North Koreans and the Chinese. Although the American public vilified Truman for this decision and for firing his insubordinate general, the decision proved to be prudent. The president knew that using nuclear weapons would only drag the Soviet Union and China fully into the conflict, which would destabilize Europe and initiate a third world war—one that might even lead to all-out nuclear war. By refusing to use nuclear weapons, Truman kept the war confined to the Korean Peninsula. The decision would later have an enormous impact on future presidents making similar decisions in Vietnam. Truman’s actions in Korea therefore demonstrated not only American resolve to contain Communism but also a desire to keep the Cold War from devolving into an open war.

The Korean War also boosted American military spending, as a result of a memorandum issued by the National Security Council, known as NSC-68. The memo recommended that Congress quadruple military and defense spending in order to contain the Soviet Union. As a result, the percentage of Congress’s annual budget spent on defense soared throughout the following years, hovering at roughly 50 percent under the Eisenhower administration. Government investment in war factories kept employment high and money flowing into the economy between 1950 and 1970, contributing significantly to the prosperous economic boom.