CAMP HANSEN, Okinawa — U.S. Marines and their Japanese counterparts have launched a series of amphibious exercises aimed at bolstering the island’s defense amid growing regional tensions. The live exercise phase of Iron Fist began Monday, involving maritime maneuvers, landing operations, and ground combat exercises. The drills will continue until March 9.

Regional Security Concerns Prompt Military Readiness

This year’s exercise comes as Japan faces ‘the most severe security environment’ since the end of World War II, according to Maj. Gen. Toshikatsu Musha, commander of the Japan Ground Self-Defense Force’s Rapid Deployment Amphibious Brigade. Speaking after the opening ceremony, Musha said the drills are designed to deter potential aggression and prevent war before it starts.

‘We cannot deny the possibility that a situation similar to the Russian invasion of Ukraine could occur anywhere in the world,’ Musha said. ‘I am confident that maintaining such a capability will deter aggression, leading to the prevention of war before it occurs.’

The increased focus on Okinawa’s defense follows a series of military actions by China around Taiwan. Chinese President Xi Jinping has repeatedly vowed to unify self-ruled Taiwan with the mainland, by force if necessary. In December, Beijing conducted another military exercise that encircled the island and included missile launches.

Additionally, China’s coast guard spent a record 357 days in 2025 patrolling waters near the Senkaku Islands, which are administered by Japan but also claimed by China and Taiwan. These developments have heightened concerns among regional allies about the security of the area.

Exercise Details and Force Composition

Exercise Iron Fist, now in its 20th edition, is taking place across Japan, including at 19 locations — three more than last year — in the Nansei Islands, according to a press release from the Okinawa Defense Office. The island chain, also known as the Ryukyu Islands, stretches from southwest Kyushu toward Taiwan.

The exercises are planned in Okinawa at the Hansen Central Training Area and Kin Blue and Red beaches, according to the Ground Self-Defense Force. Approximately 800 U.S. Marines and 2,100 U.S. sailors will participate alongside approximately 2,000 members of the Japan Ground and Maritime Self-Defense Forces.

Originally, the exercise was to include two Japanese V-22 Ospreys operating for the first time from U.S. facilities on Okinawa. However, Japan has decided to halt training with the tilt-rotor aircraft on the island, according to a spokesperson for Japan’s ground crew.

The decision is due to a change in ‘training plans’ and not to objections from the prefecture, Musha said Monday. Okinawa Prefecture, through the Okinawa Defense Office — a branch of Japan’s Defense Ministry — requested last month that the United States and Japan not fly Ospreys during the exercise.

Strategic Implications for Regional Stability

Brig. Gen. Ryan Hoyle, commander of the 3rd Marine Expeditionary Brigade, emphasized that the exercise is not targeted at any specific country but is designed to ensure that bilateral forces can respond quickly to counter aggression against Japan and other regional allies and partners.

‘Regardless of location, our combined capabilities can be applied anywhere in the region in the maritime environment,’ Hoyle said after the ceremony.

The drills are part of a broader effort to strengthen military ties between the U.S. and Japan, reflecting the growing strategic partnership between the two nations in the face of rising security challenges in the Indo-Pacific region. The exercises are expected to continue until March 9, with further developments likely to be announced as the drills progress.

The focus on Okinawa’s military infrastructure highlights its strategic importance in the region, as the island serves as a key hub for U.S. and Japanese forces. With China’s military activities in the area intensifying, the need for regional defense capabilities has never been more critical.