The Ground Self-Defense Force and the U.S. Forces in Okinawa: Close Reporting! Iron Fist 26, the largest-ever Japan-U.S. joint training exercise

Combat Training Against Virtual Enemies

Under a cloudy sky with light rain, the roaring bass sound echoed in Maenohama Seaside Park on Tanegashima Island. Parents and children taking a walk and an elderly man pulling the leash of his dog involuntarily looked up at the sky and saw the hulking body of a U.S. Marine Corps MV-22B Osprey appear from among the trees.

When it landed in the park, the rear hatch opened and a U.S. Marine carrying a rifle and mortar disembarked. They continued across the grounds and proceeded along the boardwalk, keeping a watchful eye on their surroundings.

From there, an LCAC, a hovercraft landing craft of the Maritime Self-Defense Force, landed on Nakayama Beach, located in the center of the island about 30 km to the northeast. The LCAC delivered high-mobility vehicles and other equipment.

Two days later, military vehicles landed one after another on the beach at Kushi, Nago City, Okinawa Prefecture. The U.S. Marine Corps’ new ACVs with tires for undercarriages ran up the beach and then went onto a public road.

This was a scene from “Iron Fist 26,” a Japan-U.S. joint training exercise conducted from February 11 to March 9 by the Japan Ground Self-Defense Force’s Amphibious Task Force, Japan’s version of the Marine Corps, and the U.S. 3rd Marine Expeditionary Unit in Okinawa. The U.S. military dispatched its mainstay aircraft carriers, including the Abraham Lincoln and Gerald R. Ford, to the Middle East to conduct intense air strikes against Iran while conducting the largest-ever island defense exercise with a combined U.S.-Japan force of about 4,900 participants.

Various training exercises are conducted between Japan and the U.S. throughout the year, but ‘Iron Fist’ has a slightly different flavor. The joint exercise, which has been conducted annually since 2006, is clearly designed to fight a hypothetical enemy in the form of China.

Since the beginning of the 2000s, China’s maritime and aerial threats against Japan’s Nansei Islands have intensified. The Ground Self-Defense Force, which had long focused on homeland defense security in the northern area, was forced to change its tactics, but it lacked expertise in island defense. This is when “Iron Fist,” a joint training program modeled after the U.S. Marine Corps, was initiated.

The training began with the basics, such as “clothed swimming,” in which participants swim while wearing their equipment on the U.S. mainland, and after borrowing amphibious vehicles for training, the Amphibious Task Force was newly formed in 2006. In 2011, the stage was finally moved to Japan, and training began on the islands that are the actual sites of island defense.

Training outside of training grounds is called ″dough training. This training uses actual terrain and is essential for improving tactical skills. Air Self-Defense Force fighter jets and other aircraft also train for maneuver dispersal operations to receive refueling at civilian airports in case their bases are destroyed.

On March 6, combat training was conducted against enemy forces that landed on the island. The rifles held by Japanese and U.S. personnel have radar transmitters on the end and radar receivers on their bodies, and if they are hit by enemy lasers, an alarm sounds from the receiver and at worst they are judged to be “killed in action. Amidst the rumbling sound of air envelopes, the Japanese and U.S. personnel marched solemnly forward.

The U.S. Department of Defense is wary of an invasion of Taiwan in ’27, when China will celebrate the 100th anniversary of its founding. For Japan, too, the Sino-Taiwanese problem is not a fire on the opposite shore. The sense of crisis on both sides created a sense of urgency on the ground. I hope that today’s tragedy in Iran will not happen in Far East Asia.

From the March 27/April 3, 2026 issue of FRIDAY