Did Dean Acheson Unintentionally Encourage the Start of the Korean War?

What you don’t say can sometimes matter as much as what you do say. Secretary of State Dean Acheson learned that lesson when he spoke before the National Press Club on January 12, 1950. His failure to include South Korea within his description of the U.S. defensive perimeter in Asia came back to haunt him. Critics later charged that his failure to explicitly commit the United States to defending South Korea’s territorial integrity had invited North Korea’s June 1950 invasion that plunged the United States into the three-year long Korean War.

In January 1950, Acheson had been secretary of state for nearly a year, having succeeded George C. Marshall at the start of President Harry Truman’s first full term in office. Acheson’s expertise was in Europe. As undersecretary of state from 1945 to 1947, he had been intimately involved in fashioning the Truman Doctrine and the Marshall Plan. Upon becoming secretary of state, he had to deal with the Berlin Airlift, negotiate the creation of NATO, and deal more generally with increasing U.S.-Soviet tensions. In contrast, he was less well-versed in, and passionate about, affairs in Asia.

As Acheson approached the National Press Club podium, he had reason to worry about Asia, and especially Northeast Asia, even as challenges mounted in Europe. The future of the Korean peninsula was contested. At the end of World War II, Washington and Moscow had divided control of the Korean peninsula, which Japan had occupied for half a century, at the 38^th parallel. After the war, the Soviets rebuffed the U.S. effort to have the newly formed United Nations decide the question of Korea’s reunification. In September 1948, the Soviets created the People’s Republic of Korea (North Korea) under the leadership of Kim Il Sung. Three months later, the Republic of Korea, better known as South Korea, was established.

The Truman administration was also under fire at the start of 1950 for having “lost China.” In October 1949, Mao Zedong and the Chinese Communists had finally triumphed in China’s civil war and taken  power in Beijing. The U.S.-backed Nationalist forces under the leadership of Chiang Kai-Shek had retreated to the island of Taiwan, then known as Formosa. To the great dismay of Chiang’s ardent supporters in the United States, Truman had concluded that it was futile to continue supporting the Nationalist cause. Just days before Acheson addressed the National Press Club, Truman released a statement declaring that “the United States Government will not provide military aid or advice to Chinese forces on Formosa.”

With those issues front of mind, Acheson hoped to use his speech to outline what the Truman administration was seeking to accomplish in Asia. As he noted early in his remarks: “I am frequently asked: Has the State Department got an Asian policy?” He was quick to highlight the emergence of new, independent countries across the continent and to stress that the main challenges they faced were economic rather than military. Indeed, people across the continent shared “a revulsion against the acceptance of misery and poverty as the normal condition of life” as well as “a revulsion against foreign domination.” The thrust of Acheson’s words was that the United States would support independence in Asia, help countries overcome economic privation, and resist communism because “it is really the spearhead of Russian imperialism” to “take from these people…their own national independence.”

Had Acheson stopped there, his speech might have been forgotten to all but the most dedicated Cold War historians. But he went on to outline the U.S. defensive perimeter in East Asia. He rattled off a list of countries and territories that were “essential” to U.S. national security and that “must and will be held”: the Aleutians, Japan, the Ryukyu Islands, and the Philippines. Neither South Korea nor Formosa made the list.

Acheson’s exclusion of South Korea from the U.S. defensive perimeter did not draw much comment when it was first delivered. That changed after June 24, 1950, when North Korea invaded South Korea. Suddenly, Acheson found himself in the crosshairs of administration critics, and especially Republicans, for allegedly having invited North Korea’s aggression. That line of argument seemingly received the Good Housekeeping seal of approval during the 1952 presidential campaign when Republican candidate Dwight D. Eisenhower, the retired five-star general, mastermind of the D-Day invasion, and former Supreme Allied Commander of NATO, blamed Acheson for the “political catastrophe” of the Korean War:

In January of 1950, our Secretary of State declared that America's so-called “defense perimeter” excluded areas on the Asiatic mainland such as Korea. He said in part: “No person can guarantee these areas against military attack. It must also be clear that such a guarantee is hardly sensible or necessary … it is a mistake! … in considering Pacific and Far Eastern problems to become obsessed with military considerations.”

Five months later, Communist tanks were rolling over the Thirty-eighth Parallel to assault South Korea. Twenty-seven months later the United States had suffered 120,000 casualties in a bloody, continuing conflict. Who made the mistake to which the Secretary of State referred? I leave the answer to you. 

Acheson bitterly denied the accusation, both at the time and in his magisterial memoir, Present at the Creation. He countered that his defensive perimeter had not included Australia and New Zealand either, and neither of them had been attacked. He also argued that Eisenhower’s statement in particular “tortures the facts” and “omits a significant and relevant part of what I did say.”

What Acheson had in mind, and what Eisenhower and other critics glossed over, was that Acheson did say in the National Press Club speech what would happen if an area outside of the U.S. defensive perimeter in Asia was attacked:

So far as the military security of other areas in the Pacific is concerned, it must be clear that no person can guarantee these areas against military attack. But it must also be clear that such a guarantee is hardly sensible or necessary within the realm of practical relationship.

Should such an attack occur—one hesitates to say where such an armed attack could come from—the initial reliance must be on the people attacked to resist it and then upon the commitments of the entire civilized world under the Charter of the United Nations which so far has not proved a weak reed to lean on by any people who are determined to protect their independence against outside aggression.

Critics countered that Acheson’s words here were too nuanced to have any deterrent effect.

So did Acheson’s speech help trigger the Korean War? Historians continue to debate the degree to which it did or did not. Many factors drove the start of the Korean War, and it is notoriously difficult to determine what events, facts, or words drive any leader’s decision. At minimum, though, Joseph Stalin, Mao Zedong, and Kim Il Sung had many reasons besides Acheson’s speech to doubt the U.S. commitment to South Korea. Most notably, the U.S. military had undergone a major drawdown after World War II and was ill-prepared for a possible war on the Korean Peninsula, as the U.S. scramble to respond to the actual invasion showed. At the insistence of U.S. military leaders, the United States had begun reducing the U.S. troop presence in South Korea in June 1949 because, in their judgment, U.S. forces were spread too thin. Indeed, in March 1949, General Douglas MacArthur, the commanding general of the U.S. Far East Command, gave a speech that also put South Korea on the other side of the U.S. defensive perimeter. And nine days after Acheson spoke, the House of Representatives rejected a bill that would have provided additional aid to South Korea. In short, at the start of 1950, the Truman administration, senior U.S. military leaders, and the U.S. Congress hoped to limit U.S. military commitments in Asia and not increase them. That overarching message was likely not lost on Stalin, Mao, or Kim.

But facts and nuance are routinely sacrificed in partisan battles. And Acheson could hardly claim to be above the practice of scoring political points even if he disliked being its target. As he noted in his memoir, the task of a government official “seeking to explain and gain support for a major policy is not that of the writer of a doctoral thesis. Qualification must give way to simplicity of statement, nicety and nuance to bluntness, almost brutality, in carrying home a point.” As the old saying goes, politics ain’t beanbag.

Oscar Berry assisted in the preparation of this post.