WASHINGTON – Less than a year after losing a bitter fight to tighten "buy American" requirements on purchases of military equipment, Rep. Duncan Hunter and his allies have launched a new attack against activities they see as a threat to national security and defense industry jobs. But like last year, Hunter, R-El Cajon, is facing opposition from the Bush administration, Senate Republicans and leading defense industry officials who argue that the House Armed Services Committee chairman's approach would hurt the companies he wants to help and weaken national defense. Hunter's target this year is "offsets," a factor in nearly every...