Japan has become the United States' preeminent alliance partner in the Indo-Pacific, offering greater military and economic value than the United Kingdom, according to an analysis of the evolving geopolitical landscape. This strengthened partnership is characterized by Japan's substantial increases in defense expenditure, its integral role in regional security, and its commitment to co-producing advanced weaponry with the U.S.
The alliance is critical for constraining Chinese and Russian aggression and securing vital supply chains. Japan's strategic geographic position along the first island chain is essential for maintaining U.S. access to the Indo-Pacific and deterring potential expansion by China. The U.S. maintains a significant military presence in Japan, hosting approximately 60,000 U.S. service members and an additional 35,000 civilians, making it the largest U.S. military presence outside of the United States. Japan contributes approximately 75% of the costs associated with this presence, averaging $1.5 billion annually under current agreements.
Japan's defense spending has seen a marked increase, reaching $62.2 billion in 2025 and achieving 2% of GDP in 2026, two years ahead of schedule. This upward trend has continued for 12 consecutive years, with a current five-year Defense Buildup Program allocating an estimated $275 billion through 2027. This significant investment underscores Tokyo's commitment to the alliance and its role in regional security.
Military Cooperation and Industrial Capacity
The U.S.-Japan alliance is deepening through joint initiatives in defense industrial capacity. Both nations are expanding co-production plans for advanced U.S. weapons systems, including AIM-120 AMRAAM missiles and SM-3 Block IIA interceptors, with increased production capacity in Japan. This collaboration aims to bolster allied production capabilities and address munitions shortfalls. The integration of U.S. Tomahawk missiles into the Japanese navy and the planned deployment of the Typhon missile system are expected to enhance the Japan Self-Defense Force's interoperability and counterstrike capabilities.
Intelligence and Strategic Partnerships
Tokyo is also undertaking reforms to develop a world-class intelligence community, with aspirations to potentially join the intelligence-sharing group known as the "Five Eyes." This move, while historic for Japan, is seen as a necessary step in counteracting Chinese and Russian influence operations and further solidifying the U.S.-Japan alliance.
Beyond military and intelligence cooperation, Japan is actively engaged in securing critical minerals and has been a major donor to Ukraine, pledging $6 billion in 2026 and providing $8.7 billion in budget support since 2022. In Africa, Japan has committed $30 billion since 2022, focusing on trade-oriented partnerships.
China's attempts to exert pressure on Japan through actions such as incursions into the Senkaku Islands and restricting access to critical minerals have reportedly only served to strengthen Tokyo's resolve and its alignment with the United States. This period is described as a "golden moment" for the U.S.-Japan alliance, with officials from both countries sharing a clear-eyed perspective on global opportunities and threats.