BALAD, Iraq, Nov. 1 - In one 24-hour stretch, America's successes and difficulties in this country showed themselves in the figure of Lt. Col. Nate Sassaman. On Friday, Colonel Sassaman stood before the newly elected Balad City Council, walking them through such democratic bedrocks as the secret ballot and the open meeting. On Saturday morning, after a couple of hour's sleep, Colonel Sassaman led a company of 150 soldiers on a series of house-to-house searches for weapons and guerrillas on the outskirts of town. "It's like Jekyll and Hyde out here," said Colonel Sassaman, a 40-year-old battalion commander and former...