South Korean and U.S. forces today wrapped up their four-day joint Naval drills in the Yellow Sea. On the last day of the exercises, the allies conducted a mock drill aimed at providing warships on operations with military supplies and materials. The joint maneuver mobilized some 7,300 troops, the 97,000-ton aircraft carrier George Washington and about ten navy ships. Their biggest-ever joint exercise began days after Pyongyang stunned the world with a deadly artillery strike on a South Korean island. The shelling of Yeonpyeong island killed two marines and two civilians. North Korea has warned that the four-day Yellow Sea exercises brought the Koreas closer to the brink of war.