By Wu Qiaoxi | 2026-01-23

Japanese Defense Minister Shinjiro Koizumi last week made his first visit to the United States since taking office, pairing an unusual joint workout with his US counterpart and high-level talks on alliance deterrence.

Japan and the United States agreed to expand cooperation on missile-defense production, training and exercises, and defense-industrial coordination as security tensions sharpen in the region.

On January 15, Koizumi held security talks with US Secretary of War Pete Hegseth in Washington. The two agreed to steps aimed at bolstering deterrence in the Indo-Pacific. They said expanding the alliance's presence in the Ryukyu island chain, including Okinawa, would be a top priority, and plan to expand cooperation on defense equipment and technology. They agreed to hold further talks on ramping up production of the jointly developed Standard Missile-3 Block 2A antimissile missile.

Meanwhile, the allies said they would sharpen readiness through training and exercises designed to be closer to real-world operations, spanning Japan and the rest of the first island chain. The chain includes Taiwan and the Philippines too.

"It is in order to ensure peace through strength," said Hegseth.

Koizumi cast the trip as a reaffirmation of US attention to the Indo-Pacific and to Japan, saying, "We confirmed that the Japan-US alliance remains absolutely unshakable."

Before the formal talks, Koizumi and Hegseth appeared together in matching T-shirts for a workout session, an unconventional display Koizumi framed as "physical diplomacy."

Koizumi later tweeted: "For the sake of strengthening the Japan-US alliance, I pushed through with an 'Enya kora...' kind of spirit."

Koizumi negotiated separately with US Vice President JD Vance at the White House the same day, and the two exchanged views on the regional security situation and Japan's efforts to strengthen its defense capabilities.

Sino-Japanese tensions

Koizumi's visit unfolded against rising friction between Japan and China. The neighbors' tensions escalated after Prime Minister Sanae Takaichi suggested in November that Japan could intervene militarily if China attacks Taiwan. China later announced restrictions on exports to Japan of rare earths and other dual-use items.

Before arriving in Washington, Koizumi delivered a keynote speech on January 13 at the Honolulu Defense Forum in Hawaii. Without naming a country, he warned that "opaque military buildups" were continuing, attempts to change the status quo by force were persisting in the East and South China seas and provocative military activity was intensifying in the western and southern Pacific.

He urged like-minded countries to respond collectively and rolled out a slogan -- "Make the Alliance Great Always."

Analysts and commentators have interpreted those remarks as pointing to China's actions across the region, including confrontations with Philippine vessels in the South China Sea, China Coast Guard patrols near the Japanese-administered Senkaku Islands, military drills focused on Taiwan and carrier-related activity around Japan's southwest.

Koizumi discussed security with US Indo-Pacific Command chief Adm. Samuel Paparo and said Japan would keep pushing forward Japanese-US defense cooperation as the security environment grows more severe. "Paparo said the Japan-US alliance is the most important and significant for stability not only in the region but for the world," the Japan News reported.

A central measure under discussion is a plan to reorganize US Forces Japan into a joint operational command to better coordinate with Japan on planning and combined exercises, and to support Japan if needed, Air & Space Forces Magazine reported.

One of the central efforts to deepen those ties is the transformation of U.S. Forces Japan into a joint forces headquarters that can coordinate military operations with the Japanese, plan joint exercises, and help defend the country if hostilities break out.

Japan is forming its own joint operations command to unify command across the Self-Defense Forces and improve coordination with foreign militaries, the magazine added.