United States Marines and Japan Ground Self-Defense Force soldiers stand together in formation for the opening ceremony of exercise Iron Fist 2016 on Marine Corps Base Camp Pendleton, Calif., Jan. 22, 2016. Iron Fist is and annual, bilateral amphibious training exercise held in Southern California between the United States Marine Corps and the Japan Ground Self-Defense Force. The Marines taking part in the exercise are from I Marine Expeditionary Force on Camp Pendleton. (U.S. Marine Corps photo by Lance Cpl. Timothy Valero/ Released) - United States Marines and Japan Ground Self-Defense Force soldiers stand together in formation for the opening ceremony of exercise Iron Fist 2016 on Marine Corps Base Camp Pendleton, Calif., Jan. 22, 2016. Iron Fist is and annual, bilateral amphibious training exercise held in Southern California between the United States Marine Corps and the Japan Ground Self-Defense Force. The Marines taking part in the exercise are from I Marine Expeditionary Force on Camp Pendleton. (U.S. Marine Corps photo by Lance Cpl. Timothy Valero/ Released)

A soldier with the Japan Ground Self-Defense Force’s Western Army Infantry Regiment looks out from the driver’s seat of an amphibious assault vehicle onto a simulated battlefield during training during Exercise Iron Fist 2016 at Marine Corps Base Camp Pendleton, California, Jan. 26. Iron Fist is an annual, bilateral amphibious training exercise designed to improve U.S. Marine Corps and JGSDF’s ability to plan, communicate and conduct combined amphibious operations. The exercise provides valuable training to warriors from different cultures, and the opportunity to build camaraderie between the U.S. and Japanese militaries. - A soldier with the Japan Ground Self-Defense Force’s Western Army Infantry Regiment looks out from the driver’s seat of an amphibious assault vehicle onto a simulated battlefield during training during Exercise Iron Fist 2016 at Marine Corps Base Camp Pendleton, California, Jan. 26. Iron Fist is an annual, bilateral amphibious training exercise designed to improve U.S. Marine Corps and JGSDF’s ability to plan, communicate and conduct combined amphibious operations. The exercise provides valuable training to warriors from different cultures, and the opportunity to build camaraderie between the U.S. and Japanese militaries.