Japan’s Military Shift Strengthens Security Role in Northeast Asia

• Aug 13, 2025

Japan has rapidly transformed its defence policy in recent years, moving away from its post-war pacifist stance under Article 9 of the constitution to embrace a proactive security strategy. This shift includes acquiring counterstrike capabilities, long-range missiles, and advanced defence technologies to bolster its position as a stabilising force in northeast Asia.

Under its National Security Strategy and Defence Buildup Program, Tokyo plans to purchase U.S. Tomahawk cruise missiles, enhance missile defence systems with mobile radars on Okinawa, and expand naval power with Aegis-equipped and multi-purpose destroyers. The government has approved a record defence budget of around JPY8.7 trillion ($55 billion) for 2025, part of a multi-year push to raise military spending toward 2% of GDP.

Japan’s modernisation is heavily technology-driven. It is deploying F-35B stealth fighters from Izumo-class helicopter carriers and plans to operate 42 F-35Bs and 105 F-35As, becoming the largest F-35 operator outside the U.S. The country is also investing in unmanned systems, AI, hypersonic missile research, electromagnetic detection, and space-based surveillance through its new defence technology research centre.

Strengthening alliances is central to this strategy. Japan has Reciprocal Access Agreements with the UK, Australia, and the Philippines, conducts regular joint exercises, and collaborates with the UK and Italy on a next-generation fighter program. It also works closely with the U.S. in forums like the Quad and trilateral drills with South Korea, reinforcing deterrence against regional threats, particularly from China.

Japan’s capabilities challenge China’s anti-access, area-denial strategy, particularly near Taiwan and the East China Sea. Beijing has voiced concern, with state media warning that Tokyo’s rearmament could spark an arms race. Nonetheless, Japan argues its build-up is a response to China’s own military expansion.

In a major shift, Japan has entered the arms export market, securing a $6.5 billion deal to supply Mogami-class frigates to Australia — its first major lethal arms export since World War II. Revised export rules will also allow the sale of next-generation fighters to allied nations, expanding Tokyo’s influence in the Indo-Pacific.

By increasing defence spending, embracing advanced technologies, expanding partnerships, and entering the arms market, Japan has positioned itself as a key pillar of security in northeast Asia, countering threats while reassuring regional allies.