On October 19, 1950, the worst fears of President Truman came true, when despite General Douglas MacArthur's confident assessment that the Chinese would not cross the Yalu River and interfere with the Korean War, 200,000 Chinese soldiers streamed across the river and attacked UN/South Korean forces. MacArthur had told Truman only about 100,000 Chinese soldiers were near the Yalu, a gross underestimate. Even after initial fighting with Chinese, MacArthur did not grasp the scope of the disaster.
Digging Deeper
North Korea had invaded South Korea earlier that year, surprising the US and its South Korean ally. Korea had been split in 2 after World War II, with the North (above the 38 Parallel) being communist and aligned with the USSR and Red China, and the South maintaining a capitalist democracy aligned with the West.
