U.S. 'Worried About S.Korea's Bolder Deterrence Strategy' The U.S. is worried about South Korea's more aggressive deterrence strategy against North Korea, which was formulated after the North's attacks on the Navy corvette Cheonan and Yeonpyeong Island last year, a government source said Sunday. The military has been instructed to strike back faster and more aggressively in the event of any further provocations by the North. "After the North's attack on the Cheonan last year, Gen. Walter Sharp, the commander of the U.S. Forces Korea, expressed concerns about our military's increase of firepower near the demilitarized zone," the government source said....