>China followed with massive, highly disciplined infantry waves that effectively fought the UN coalition to a stalemate.

just to clarify what "effectively fought" means, the Chinese entered the war when the ROK+US+UN forces had reached as far as the Yalu River, and yes their "infantry waves" response, i.e. lightly armed human waves, pushed the anti-communists back but at very, very high cost:

"North Korean casualties are estimated at around 1.5 million, including both military and civilian losses, while Chinese military casualties are estimated to be around 400,000 to 600,000."

"South Korean military losses during the Korean War were approximately 137,899 dead, with additional casualties including 24,495 missing and 8,343 captured. The United Nations forces, primarily composed of U.S. troops, suffered around 36,574 deaths, with total UN losses estimated at about 210,000 dead and missing."

that's about 2 million or more killed vs 210,000