Kim Il Sung (1912–1994) was the dictatorial leader of North Korea from shortly after World War II until his death in 1994.
As a young man, Kim led guerrilla forces against the Imperial Japanese Army until he was forced to flee Korea in the late 1930s. There's some debate about what he did next—the North Koreans claim that he organized the Anti-Japanese Guerilla Army in Manchuria, but other accounts suggest that he fought in the Russian Red Army.
By the end of World War II, Kim had returned to the Korean peninsula along with Russian forces. Having become an ardent communist, Kim went on to lead the first government in the North: the People's Democratic Republic of North Korea.
In the early years of the Cold War, Kim sought to reunify all of Korea under his own communist leadership. In 1949 and early 1950, it seemed that he might have more support among the Korean populace than the equally autocratic leader of South Korea, Syngman Rhee. But Rhee shored up his support by mid-1950, meaning that when Kim invaded the South in July of that year, his forces were not—as he hoped and expected—greeted as liberators. Kim led North Korea throughout the Korean War, at different times nearly achieving victory and nearly falling to defeat.
He agreed to the armistice of 1953, and ruled his country with an iron fist for another 40 years. In the later years of his regime, North Korea slid farther and farther into poverty and authoritarianism.
General Douglas MacArthur (1880–1964), one of the most powerful military officers in modern American history, was the Allied Commander of the Southwest Pacific Theater during World War II and the Commander in Chief of the Far East (CINCFE) in the postwar period.
He accepted the Japanese surrender aboard the U.S.S. Missouri in September 1945, then acted as supreme commander over the occupation of Japan. He commanded all American forces in the Korean War until being relieved of his command by President Harry Truman in April 1951.
MacArthur was born into a military family, with generations of male ancestors who'd once fought Native Americans in the American West. He attended West Point and became the youngest divisional commander in France during World War I. He went on to become Chief of Staff of the U.S. Army from 1930 to 1935. He commanded American forces in the Philippines during World War II.
In Korea, MacArthur organized a brilliant amphibious attack behind enemy lines at Inchon, nearly allowing the United States to win the war in the fall of 1950. However, MacArthur badly underestimated the threat of Chinese intervention, and was caught completely off-guard by the Chinese advance of November 1950. His forces thrown into retreat, MacArthur demanded a massive retaliation—possibly involving nuclear weapons—against China itself. President Truman denied his request, fearing such an escalation would lead to World War III.
The two stubborn leaders became enmeshed in a nasty public dispute over American policy, leading to Truman's decision to relieve the general of his command on grounds of insubordination. MacArthur received a hero's welcome in cities from San Francisco to New York after he was discharged in April 1951, but subsequent Senate hearings over his dismissal largely discredited him in the public eye, and he faded from public prominence after an unsuccessful bid for the Republican presidential nomination in 1952.
Dr. Syngman Rhee (1875–1965) was an American-educated Korean exile who returned to his country to become the first President of South Korea in 1948. A fierce anticommunist but also an unpopular autocrat, Rhee led his nation—rather ineffectually—throughout the Korean War.
As a young man, Rhee was imprisoned from 1897 to 1904 for his activism in support of internal reforms in Korea. Following his release, Rhee traveled to the United States, attended Princeton, and became the first Korean student to receive a PhD in America. He then returned home and participated in the Korean rebellion against the Japanese occupation in 1919. When that effort was quashed, Rhee fled again and did not return until the Japanese were defeated in August 1945.
By this point, he was approaching 70 years old and had become quite conservative and a ferocious anticommunist. His presidency largely failed to make substantial gains in the quality of life for the war-torn Koreans, and Rhee employed authoritarian measures to maintain power. He ardently clamored for war with the North.
After North Koreans crossed the 38th parallel in June 1950, Rhee ordered his army and police to murder domestic political opponents. As many as 100,000 people are believed to have been killed in this "Summer of Terror." The executions were supposed to prevent southern leftists from reinforcing the rapidly advancing northern troops, but Rhee's attention to eliminating political opponents rather than fighting North Korean troops led to the near-collapse of his country.
Harry S. Truman (1884–1972) became the 33rd President of the United States upon the death of Franklin D. Roosevelt in April 1945.
Truman, who'd only a high-school education and had been in office as vice president for just 82 days before Roosevelt's sudden death, inherited the monumental task of leading the United States through the end of World War II and the beginning of the Cold War. Truman—who was, while in office, one of the least popular presidents in modern American history—won a surprising second term by defeating Republican Thomas Dewey in the election of 1948.
The Cold War began under Truman's watch, as the president came to believe that he must take a hard stance to contain the expansionistic tendencies of the Soviet Union. The president's Truman Doctrine committed the United States to a policy of supporting foes of communism everywhere in the world. Truman's failure to lead the United States to victory in the Korean War led to a severe decline in support for the president's policies among the American people.