CAMP SAYLIYA, Qatar, April 3 — Day after day since the beginning of the war, Brig. Gen. Vincent K. Brooks has described the advance of American forces toward Baghdad. Today, General Brooks, the chief military spokesman for Central Command, said that American soldiers were at the gates of the city, ready to enter whenever and wherever they choose. So it was a bit jarring to hear a television reporter from Hong Kong question the general about what would happen if the American offensive suddenly collapsed. "Where would the coalition troops retreat to?" he asked. It was a question ready-made for...