The Koreas | Security | East Asia

The Korean War at 70

Remembering the outbreak of a conflict that still echoes today.

By Yoav J. Tenembaum for
The Korean War at 70

Refugees flee hostilities during the initial stage of the Korean War.

Credit: U.S. Defense Department

Seventy years ago, the Korean War broke out. On June 25, 1950, North Korea invaded South Korea, leading to one of the gravest crises of the Cold War.

For the leaderships of South Korea and the United States, the North Korean attack constituted a strategic surprise for which they were totally unprepared. Yet, within two days, the administration of President Harry Truman in the United States managed to mobilize the United Nations Security Council into adopting two crucial resolutions. The first criticized the North Korean invasion and called for its armed forces to withdraw immediately from South Korea; the second called on members of the United Nations to lend assistance to South Korea in its efforts to repel the invasion.

Truman set a clear objective, to liberate South Korea, and chose what he believed to be the most appropriate means to achieve it: eliciting international support as part of a diplomatic campaign aimed at delineating a legal framework that would legitimize the use of force. To be sure, apart from defining a policy and adopting the tools to carry it out, the Truman administration took advantage of propitious circumstances that rendered its task considerably easier.

The Soviet Union had been boycotting the United Nations Security Council in protest at the refusal of that body to accept Communist China as a member instead of the Nationalist government, now relegated to Taiwan. The absence of the Soviet representative allowed the United States to pass the two aforementioned resolutions without a veto being cast by the Soviet Union.

An international force was created, led by the United States, to help repel the invasion of South Korea. This was to be an international effort, sanctioned by the United Nations. Truman called it “a police action,” denoting a legitimate action by an authoritative entity.

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Although caught by surprise, the United States had witnessed how communism was on the advance, gradually but surely: the Berlin Crisis of 1948-1949, the communist coup in Czechoslovakia in 1948, the victory of the communist forces led by Mao Zedong in the civil war in China in 1949, and the loss of the U.S. atomic monopoly to the Soviet Union in 1949.

The invasion of South Korea by North Korea was thus perceived by the United States to be both a continuation of a process but also, in a sense, a turning point. Truman compared it to the German remilitarization of the Rhineland in 1936. In other words, the United States should do in 1950 what Britain and France failed to do in 1936, and take decisive action to head off a worse crisis in the future. Communism was thought to be an expansionist ideology led by a powerful Soviet Union.

The Truman administration had already enunciated its policy toward communism in 1947. The “Truman Doctrine” translated into policy the conceptual precepts of the containment policy advocated by U.S. diplomat George Kennan. Believing that the Soviet Union would take advantage of any opportunity to expand politically and territorially, Kennan recommended that the United States deploy the political, economic and propaganda tools at its disposal to prevent it. Contrary to Nazi Germany, the Soviet Union could be contained by a rational policy of deterrence.

The Soviet and Chinese leadership had aided North Korea in its invasion plans, believing that the United States would not react militarily. They were surprised when it did. When the United States and South Korea decided to cross the 38th parallel, the boundary separating North and South Korea, in a bid to unite the two Koreas under a non-communist regime, their surprise turned into anxiety.

To be sure, China warned the United States through various intermediaries that it would intervene in the war as U.S. and South Korean troops were marching further north, toward the Chinese border. In defining his goals, Truman had made clear to his advisers that he wished to liberate South Korea without getting embroiled in a war with the Soviet Union and/or China. However, China’s warnings were dismissed by U.S. officials who argued that China was bluffing. The CIA assessed that neither China nor the Soviet Union would intervene directly in the war so as to avoid a total confrontation with the United States.

China intended to deter. The problem with deterrence is that it fails if it is not perceived to be credible.

The United States was yet again caught by surprise. On November 26, 1950, the Chinese army became directly involved in the war as hundreds of thousands of its soldiers crossed the border to repel the U.S. and South Korean attack on North Korea. What Truman least wanted was actually happening. What began as an internationally-sanctioned diplomatic and military endeavor to liberate South Korea turned into a major military confrontation between the United States and China.

China had backed North Korea in its invasion of South Korea, but now needed to defend North Korea from political extinction. Apart from that, North Korea was important also as a buffer against the United States. The Chinese leadership feared that the ultimate objective of the United States was to attack China and topple the communist regime that had been in power since 1949.

That was certainly not Truman’s objective. Indeed, when General Douglas MacArthur, who headed the international force in Korea, urged Truman to expand the war by attacking mainland China, he refused. An attack on mainland China might enlarge the war even further, he feared, leading perhaps to the direct intervention also of the Soviet Union. When MacArthur made public his disagreement with Truman, the latter fired him.

This was an act of supreme leadership by Truman, who knew that MacArthur was enormously popular in the United States, and that his decision might not be welcomed by public opinion. However, he strongly believed that an elected president must prevail over a general. The latter could advise, try to persuade a president, but once a decision had been taken by a president, a general could either implement it or resign. Any other option was unacceptable.

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Truman wanted to confine the war to the Korean theater. The direct intervention of China was a most unwelcome development, which he hoped to contain without enlarging the war beyond Korea.

The Korean War would last until July 1953. The ceasefire agreement would restore, in general terms, the territorial and political status quo ante that prevailed prior to the outbreak of war in 1950.  This raises the question as to whether the decision during the war by the United States and South Korea to cross the 38th parallel was, with the benefit of hindsight, correct or not. Could the war have finished much earlier than it did, and with considerably fewer casualties? Shouldn’t the United States and South Korea have deemed the liberation of South Korea as a victory and stopped the war after having achieved it?

The original decision by the United States with regard to the North Korean invasion was understandable and justifiable, in the short run, and wise in the long run, as it conveyed a deterrent message to North Korea and its communist allies, the Soviet Union and China. An implicit red-line had been drawn by the United States conveying its readiness to defend South Korea, which has outlived many a crisis up to the present. In that respect, the Korean War was a turning point.

With the benefit of hindsight, the decision by the North Korean leader, Kim Il Sung, to invade South Korea turned out to be a serious mistake. He could have paid more dearly than he did had it not been for the direct intervention by China. That could have been avoided, to be sure, had the United States and South Korea not crossed the 38th parallel during the war. However, it ought to be stressed: China and North Korea crossed the 38th parallel in their counteroffensive, which was designed to repel the U.S. and South Korean forces from North Korea. In other words, North Korea and China were bent on destroying South Korea as a separate sovereign entity. Whether the decision by the United States and South Korea to cross the 38th parallel was correct or not should not be assessed from a moral point of view, but rather from a pragmatic perspective. North Korea had started the war, and it could have ended it with the help of its Chinese ally by stopping at the 38th parallel. It didn’t. The war lasted until July 1953 not only because the United States and South Korea had resolved to unite both Koreas under a non-communist regime, but also due to the decision of North Korea and China to attempt, once again, to obliterate South Korea, rather than stop the war at the 38th parallel.

Dr. Yoav J. Tenembaum is a lecturer at the School of Political Science, Government and International Affairs, at Tel Aviv University, Israel. Tenembaum holds a doctorate degree in Modern History from Oxford University and a master’s degree in International Relations from Cambridge University.