Within a year of the end of the Chinese Civil War, the Americans severely tested Mao’s methods in Korea:
During the early days of the Chinese intervention — beginning in October 1950 — the People’s Liberation Army (PLA) badly misjudged the killing effect of American artillery and tactical air power. Pushed too quickly into maneuver warfare, the Chinese massed in the open, often in daylight, to expand their control over the northern portions of the Korean Peninsula. They extended their narrow lines of communication farther down the mountainous spine of Korea as they advanced. But they soon found their logistic support exposed to the terrible effects of American air power. The Chinese paid a horrific price for their haste. Their spring 1951 offensive sputtered to a halt as U.S. artillery and aerial firepower slaughtered Chinese soldiers in masses, while air interdiction cut their supply lines and forced a retreat back across the Han.
Brutal experiences led quickly to sober lessons relearned from the Chinese Civil War. As a highly skilled complex adaptive system the Chinese Army quickly adjusted to the actual conditions of this new war. Over the next two years, subsequent Chinese attacks remained limited and controlled. The Chinese high command learned to hold most key logistic facilities north of the Yalu River well out of reach of U.S. air attacks. South of the river the Chinese dispersed and hid their forces while they massed only in the period immediately before launching an attack. Because their forces were so difficult to locate and so easy to transport, mortars became the Chinese weapon of choice. PLA soldiers moved at night and chiseled their front lines of resistance deep into hard, granite mountains. American casualties soon mounted, while the Chinese stabilized their casualties at a rate acceptable to their political leadership. Far more Americans died in combat during this “stability phase” of the war than during the earlier period of fluid warfare. A cost acceptable to the Chinese became too costly to the Americans. The result was an operational and strategic stalemate. To the Chinese, stalemate equaled victory.