Insurgents gunned down four U.S. service members west of Baghdad on Monday, and South Korea said it would go ahead with plans to send thousands more troops to Iraq despite a threat by Iraqi kidnappers to kill a South Korean seen pleading for his life on a videotape. Elsewhere, Iraq resumed oil exports Monday, six days after attackers blasted pipelines carrying crude oil to the Basra terminal on the Persian Gulf. Iraqi officials have announced stepped-up measures to protect the oil industry — the foundation of the nation’s economy. Full Story