A U.S. Marine Corps infantryman with the 31st Marine Expeditionary Unit, 3rd Marine Expeditionary Brigade (Forward) participates in a mock assault during exercise Cobra Gold 2011 in Hat Yao, Thailand, on Feb. 11, 2011. Cobra Gold is a regularly scheduled joint/combined exercise designed to ensure regional peace and strengthen the ability of the Royal Thai Armed Forces to defend Thailand or respond to regional contingencies.