TOKYO, June 27 — Japan’s upper house of parliament has approved legislation that will rename the country’s Air Self-Defense Force as the “Air and Space Self-Defense Force,” a symbolic but consequential overhaul that formally designates outer space as a new operational domain for the Japanese military.
The amendments to the Act for Establishment of the Ministry of Defense and related laws were passed by the House of Councillors on June 26 and had previously cleared the House of Representatives in late April, completing the legislative process. The bill explicitly defines outer space as a new operational domain for the Self-Defense Forces, alongside land, sea and air, and changes the Japanese-language name of the air service to reflect that expanded remit.
According to Japan’s Ministry of Defense, the renamed force is expected to be formally inaugurated within the current fiscal year, which runs from April 2026 to March 2027. It marks the first time the air arm of the Self-Defense Forces has been renamed since its creation in 1954.
At the centre of the restructuring is a new specialised unit known as the Space Operations Group, which will be commanded by a senior officer from the air service. The unit traces its origins to a 20-person Space Operations Squadron set up in 2020, which was upgraded to a Space Operations Wing in 2022 and further expanded to roughly 670 personnel as the Space Operations Wing earlier this year. Under the new structure, the formation is expected to grow to about 880 personnel.
Officials have described the unit’s missions in defensive terms, citing satellite launches, space situational awareness, tracking of orbital debris and the protection of communications and navigation infrastructure that underpins both civilian life and military operations. Japan’s defence ministry has previously stated that strengthening space-domain capabilities is intended to support faster and more accurate battlespace awareness.
The legislation goes beyond the renaming. It increases the number of state ministers for defense from one to two, broadens re-employment support for retired Self-Defense Forces personnel and raises certain benefits paid to former service members. To strengthen Japan’s defence posture in the southwestern island chain, the 15th Brigade of the Ground Self-Defense Force, headquartered at Naha in Okinawa, will be upgraded to a division.
Defense Minister Shinjiro Koizumi told reporters after a cabinet meeting that the additional state minister post and the renaming of the air service were indispensable for strengthening Japan’s defence capability, and described the changes as necessary to adapt the organisation to what he called the most severe and complex post-war security environment.
The vote drew criticism from opposition lawmakers and civil society groups. Japanese Communist Party leader Tomoko Tamura argued during the parliamentary debate that the change formally assigns the Self-Defense Forces a combat role in space and risks accelerating an arms race in orbit. Social Democratic Party leader Mizuho Fukushima questioned the legal clarity of treating “space defence” as a settled premise while the scope of collective self-defence remained, in her view, ambiguous. The Aichi Prefectural Peace Committee said in a social media post that expanding the military domain into outer space would aggravate tensions in the region.
The renaming reflects a longer-term trend in Japanese security policy. Tokyo’s three updated national security documents, released in late 2022, had already flagged the planned change of name and the build-up of dedicated space units. Japan has also gradually deepened cooperation with the US Space Force, including data sharing on space situational awareness and joint exercises focused on space-domain scenarios.
For regional capitals, the most closely watched element is how quickly the new force translates an expanded legal mandate into operational capability, and whether the larger Space Operations Group will move from satellite protection and debris tracking toward more contested missions. Officials in Tokyo have so far framed the unit’s role as defensive, while critics argue that the boundary between protective and offensive space activities is becoming increasingly blurred.
