President Bush's agenda in Asia this week is front-loaded with trouble on the continent: nuclear worries, political repression, recovery from natural disaster. Then comes plenty of sports. Bush embarks Monday on his last venture as president to the Far East, a trip built around the Olympic Games in Beijing. The president will stop en route at an Alaskan Air Force base to speak to military personnel and get his plane refueled, then fly through the night to South Korea. ...