US-Japan Security Push Expands Arms and Military Drills

Japan Defense Minister Shinjiro Koizumi and U.S. Defense Secretary Pete Hegseth agreed Wednesday to deepen cyber and military cooperation as Japan confronts data breaches affecting millions. The two governments also plan to expand missile production and joint exercises. Their talks took place on the sidelines of an expanded Association of Southeast Asian Nations defense ministers' summit on the Philippine island of Cebu. Officials and defense institutions made the security decisions; Japan's Defense Ministry said the cyber incidents threatened citizens' lives and economic activity.

Millions Exposed, Defense Production Expanded

Japan's Defense Ministry said the two chiefs agreed to strengthen coordination against “a series of malicious cyberactivities — including large-scale leaks of personal information — both domestically and internationally.” Japan has faced repeated cyberattacks and data breaches in recent weeks, exposing personal information belonging to millions. Stronger coordination aims to prevent serious effects on citizens' lives, economic activity and both countries' security.

The officials also agreed to bolster defense-industrial cooperation, including a plan to expand production of SM-3 Block IIA missiles. They announced plans to establish a final assembly and check-out facility in Japan for advanced medium-range air-to-air missiles, or AMRAAMs. Analysts said the United States has significantly depleted its missile stockpiles during its ongoing war against Iran, including its SM-3 interceptor stockpile. The meeting brought cyber defense, industrial production and military planning together under one official security agenda.

Koizumi reiterated Tokyo's protest over the alleged murder of an Okinawa woman by a U.S. Marine earlier in October, urging the United States to take effective measures to prevent similar incidents. The protest came alongside alliance planning and expanded weapons cooperation. Hegseth called the U.S.-Japan alliance “indispensable.”

More Investment, More Realistic Training

The two defense chiefs stressed increased defense investment and continued strategic alignment to strengthen deterrence and implement an effective denial defense in the First Island Chain, which stretches from Japan to Borneo. Hegseth wrote on X that the talks focused on advancing a “shared vision of peace through strength.” He said: “Our strategic alignment is essential to building a credible denial defense — supported by increased investment, greater access, more realistic training, and stronger production of the munitions our forces need.” U.S. and Japanese officials say the strategy aims to make aggression physically infeasible or unacceptably costly, deterring an attack.

The meeting came a day before the United States and Japan were to conclude the Keen Sword joint military exercises, focused on the southwestern islands near Okinawa Prefecture. Tokyo said the ministers agreed to “move forward with even greater urgency” on advanced and realistic joint training, including “unprecedented live-fire exercises.” The exercises would flexibly use facilities such as airports and seaports to rehearse distributed operations designed to keep forces from becoming enemy targets.

China has increased military activity in the area and around self-ruled Taiwan, which Beijing claims as its own. Neither government's statement directly named China. Japan's Defense Ministry said the ministers agreed to “closely coordinate and respond to all contingencies,” while considering “neighboring countries' expansion in quality and quantity of military capabilities and their intensification of military activities.”

Japan's administration is preparing to revise three key national security documents by the end of 2026. Koizumi said Wednesday he had updated Hegseth on discussions about the revisions. It wasn't immediately clear whether they discussed Washington's push for Tokyo to increase defense spending. Tokyo was reportedly considering a new midterm target of 3.5% of gross domestic product, matching the figure of NATO, South Korea and other U.S. allies. The Defense Ministry requested nearly ¥9 trillion ($57.7 billion) in August for the next fiscal year. Its budget was likely to exceed ¥10 trillion after year-end additions following the revisions.

Allies Ask What the Commitments Mean

Southeast Asian counterparts were expected to question Washington's commitment to the Indo-Pacific when Hegseth attended the Cebu summit Wednesday. The Pentagon said his presence would reaffirm U.S. commitment to “peace through strength.” Analysts said regional officials might seek clarity about the Iran war's endgame, U.S. expectations of allies and partners, and how military demands related to Iran fit with U.S. commitments in the Indo-Pacific.

“They will want to seek answers from the United States regarding certainty towards alliances and partnerships,” said Collin Koh, a security scholar at Singapore's S. Rajaratnam School of International Studies. “And of course, the bigger elephant in the room is how does that juxtapose with US commitment to the Indo-Pacific or Western Pacific theatre.” U.S. and Israeli strikes launched the Iran war on February 28. The conflict disrupted shipping and oil markets, exposing Southeast Asia's vulnerability to imported-fuel shocks and raising energy security on ASEAN's agenda.

Greg Poling, director of the Asia Maritime Transparency Initiative, said Hegseth could address China, the disputed South China Sea and U.S. commitments to treaty allies. “Most will want reassurance about U.S. commitment to the region, despite the political turmoil in Washington and the weakening of both U.S. capabilities and readiness by the war in Iran,” Poling said.

The Philippines, a U.S. treaty ally, has seen relations with Beijing deteriorate amid repeated confrontations in the disputed South China Sea, Chinese sanctions and the recent summoning of the Chinese ambassador. Before the summit, the Philippine military said it monitored and shadowed China's Liaoning aircraft carrier group as it passed through waters off the southern Philippines toward the Celebes Sea. Koizumi was scheduled to meet Philippine, Indian and South Korean counterparts and join a quadrilateral meeting with the U.S., Philippine and Australian defense chiefs. He wasn't scheduled to meet Chinese Defense Minister Dong Jun; China said Dong would skip the meeting and send its defense attaché in the Philippines instead.

Poling said firmer signals were more likely among like-minded partners, including the Squad — the United States, Japan, Australia and the Philippines. He also said the Philippines had to balance “aspirational cooperation” on energy connectivity, the digital economy and coast guard cooperation with rising tensions and stalled progress on a South China Sea code of conduct. “I'd expect tactical cooperation on the ADMM workstreams ... but no strategic alignment on the South China Sea or other thorny issues,” he said. The scheduled talks may produce cooperation on particular workstreams; the underlying disputes and uncertainty over U.S. commitments remain on the table.