Japan redefines post-war defence posture with record budget and counterstrike capabilities
A record $58bn defence budget for fiscal year 2026 funds the deployment of long-range missiles and Tomahawk systems as Japan seeks to secure the Nansei Islands against perceived threats from China.
Japan has enacted a significant strategic pivot by allocating a record $58bn defence budget for fiscal year 2026 to construct a southern shield along the Nansei Islands. This initiative, driven by deepening concerns over China and scepticism regarding US security guarantees under President Donald Trump, involves legal reinterpretations to permit collective self-defence and the acquisition of long-range counterstrike capabilities.
The deployment of long-range missiles capable of striking China to Kumamoto Prefecture in late March 2026 marks the first time since 1947 that Japan has positioned such systems on Kyushu. Defence Minister Shinjiro Koizumi described the current situation as the most severe and complex security environment the nation has faced since the post-war era, necessitating a complete shift in defence posture towards the southwest.
This new front focuses heavily on the Nansei or Ryukyu Islands, which run from Kyushu to within 100km of Taiwan. These islands form a natural barrier dividing the East China Sea from the Philippine Sea and are a critical part of the United States-led First Island Chain maritime defence strategy, which aims to keep Chinese forces out of the Pacific.
The strategy incorporates a major shift in Japan defence policy towards acquiring counterstrike capability that would allow the Japan Self-Defense Forces to hit back if attacked, stretching the legal definition of what constitutes self-defence. As part of this strategy, Tokyo is due to acquire 400 US-made Tomahawk missiles, which can be launched from submarines and naval vessels.
These moves reflect growing concern in Tokyo about its longtime ally, the US, and its ability or willingness to defend its allies. A 2025 survey by Japan's Asahi Shimbun indicated that 77 per cent of respondents doubt that the US would protect Japan in a military crisis, a sentiment fuelled by President Trump's America First policy and combative relationship with longtime allies.
Japanese Prime Minister Sanae Takaichi stated in December that a Taiwan conflict could prove to be a survival-threatening situation for Japan, which hosts multiple US military bases. This underscores the urgency behind the upcoming release of the national security strategy covering 2026 to 2030, which is expected to incorporate lessons from conflicts in Ukraine and Iran regarding drones and supply chains.
In its latest legal adjustment, the government also approved the export of lethal weapons this month as it moves to build up a domestic drone industry. This approach allows Japan to maintain a modern military capability under a constitution that explicitly forbids war, relying on reinterpretation rather than formal amendment to navigate the evolving security landscape.
