pproved orders for UN forces to cross the 38th parallel and push the enemy above the Yalu River, which separated North Korea from China. Despite repeated warnings from the Chinese that they would enter the war if the Americans came near the Yalu, UN forces crossed into North Korea on October 7 and later captured Pyongyang, its capital city (Summers, 141-144,305).
             By October 25 some advance units had reached the Yalu; there they came into contact with Chinese "volunteers" who had moved into North Korea. After hard fighting in which MacArthur's
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