A vanguard force of about 150 U.S. Marines landed on the beaches of Mogadishu, this time to help bring safely to an end a well-intentioned but unsuccessful U.N. effort to help foster the establishment of a democratic government. Two years ago, U.S. troops arrived amid floodlights, TV cameras and reporters, as they set out to feed thousands of starving Somalis. Today, the Pentagon arranged coverage of the low-key landing by blurry nightscope. As 32 U.S. ships wait offshore, a main force of 2,000 Marines and Italian soldiers is due to land within 24 hours to help evacuate 2,400 Pakistani and Bangladeshi peacekeepers, the remnants of an international force that once numbered 38,000 from 21 nations. The international famine-relief effort saved tens of thousands of lives, but the subsequent peacekeeping efforts degenerated into a low-grade war between clan militias and U.N. forces.