Japan’s defense cooperation strategy with Southeast Asian nations has undergone a significant transformation since the mid-2010s, shifting beyond the boundaries of traditional military partnerships. This evolution reflects Tokyo’s broader ambition to build stronger and more comprehensive defense ties across the region.

In the 2025 Global Firepower Index, Japan's military ranks as the 8th most powerful in the world, maintaining a strong defense presence in the Asia-Pacific region. It is recognized for its advanced and modern air force, a strong ground force, and a robust military-industrial complex capable of local production. Japan's military strength is further bolstered by its defense partnership with the United States and its strategic alliances with other regional powers like South Korea and the Philippines.

Through an expanded approach encompassing equipment transfers, regional joint exercises, and strategic dialogues, Tokyo continues to reinforce its defense diplomacy in Southeast Asia. The foundation of this policy shift lies in the creation of new legal and political frameworks designed to deepen Japan’s security engagement under the principles of “standards and norms.”

One of the most important instruments driving this new direction is the “Three Principles on Transfer of Defense Equipment and Technology,” first introduced in 2014 and recently reviewed in 2023–2024.

According to Takeshi Yuzawa, Professor of International Relations at Hosei University, this framework has triggered a record surge in Japan’s defense equipment transfers − the highest since 1967.

The implementation of this transfer policy has already materialized through a series of key agreements with ASEAN member states. Japan’s record of defense and technology transfers includes partnerships with the Philippines (2014), Malaysia (2018), Indonesia (2021), Vietnam (2021), Thailand (2022), and most recently, Singapore (2023).

Beyond equipment and technology, Japan has also strengthened non-traditional cooperation through initiatives such as the “Vientiane Vision,” launched in 2016. The vision focuses on using dialogue and collaborative frameworks to define regional aspirations and enhance capacity-building efforts among ASEAN countries.

“This reflects the foundation of Japan’s foreign defense policy,” Yuzawa said during a public lecture at the Foreign Policy Community of Indonesia (FPCI) on Wednesday, October 8, 2025.