U.S.: Iraqi Troops on Verge of Collapse By DAVID CRARY .c The Associated Press U.S. Marines and infantrymen surged forward Thursday into the outskirts of Baghdad, yet to be slowed by the Republican Guard. A U.S. spokesman said the Iraqi forces appeared on the verge of collapse. Lead units of the multi-pronged U.S. assault force were within about 10 miles of Baghdad, approaching Saddam International Airport. Army troops closed in from the southwest after crossing the Euphrates River; Marines advanced from the southeast in a long column along the Tigris River. Paving the way, special forces infiltrated some Iraqi command...