The annual Key Resolve/Foal Eagle exercise started 28 February 2011, and employed almost 13,000 U.S. troops and more than 200,000 South Korean troops, as well as a U.S. Navy carrier strike group led by the USS Ronald Reagan.[32][33] Key Resolve involved computer-based military simulations that ran from 10 March 10, while Foal Eagle field training programs were completed by 31 March 2011