U.S. marines march during a joint military exercise in Tarlac Province, the Philippines, April 12, 2013. The Philippines and the U.S. held its 29th annual joint military exercise with at least 8,000 American and Filipino soldiers participating in the training. The joint military exercise, more known as Balikatan, which means "shoulder-to-shoulder" in Filipino, is held from April 5 to 17. (Xinhua/Rouelle Umali)