evidence: Initially, this new strategy was a success. The Inch’on Landing, an amphibious assault at Inch’on, pushed the North Koreans out of Seoul and back to their side of the 38th parallel. But as American troops crossed the boundary and headed north toward the Yalu River, the border between North Korea and Communist China, the Chinese started to worry about protecting themselves from what they called "armed aggression against Chinese territory." Chinese leader Mao Zedong (1893-1976) sent troops to North Korea and warned the United States to keep away from the Yalu boundary unless it wanted full-scale war. [...] In July 1951, President Truman and his new military commanders started peace talks at Panmunjom. Still, the fighting continued along the 38th parallel as negotiations stalled. Both sides were willing to accept a ceasefire that maintained the 38th parallel boundary, but they could not agree on whether prisoners of war should be forcibly "repatriated." (The Chinese and the North Koreans said yes; the United States said no.)