The Ambassador's Son by Homer Hickam
They had two weeks to accomplish a mission no soldier should ever have to do. They were going after one of their own - David Roosevelt Armistead - a hero up for the Medal of Honour, and an ambassador's son, who was now missing in the thick, jungled climes of the Solomons. So while American forces blast away at one god-forsaken Pacific atoll after another, Coast Guard captain Josh Thurlow must make a desperate venture north into Japanese-held islands.