Clued-in | Japan's military expansion raises concerns over 'Pearl Harbor incident' in space

Japan's House of Councillors recently approved the Bill Partially Amending the Act for Establishment of the Ministry of Defense, giving the green light to reorganize and rename the Air Self-Defense Force into the Air and Space Self-Defense Force. It also decided to rename the Space Operations Wing as a space operations command. This marks a significant step in Japan's military expansion into outer space. Japanese media have pointed out that the move is not merely a name change, but a milestone in the expansion of Japan's security strategy.

In recent years, in pursuit of its so-called goal of becoming a "normal country" capable of waging war, Japan has repeatedly sought to break free from the constraints imposed by international documents such as the Potsdam Declaration and its pacifist Constitution. It has sharply increased defense spending for 14 consecutive years, accelerated the development of offensive military capabilities and weapons systems, and gradually extended its military expansion from land, sea and air into space.

Japan's space defense budget surged from 50.6 billion yen (about $312 million) in fiscal 2020 to 540.3 billion yen in fiscal 2025. In May 2020, Japan established the Space Operations Squadron with around 20 personnel. In March 2022, the unit was expanded into the Space Operations Group, increasing its size to about 310 personnel. In March this year, it was upgraded into the Space Operations Wing, with its personnel rising to around 670. Following a future upgrade into a space operations command, its size is expected to reach about 880 personnel. Such an extraordinary pace of expansion indicates Japan's urgency to develop operational capabilities in space.

By upgrading and expanding the Air Self-Defense Force into the Air and Space Self-Defense Force and establishing a dedicated space operations command, Japan aims to make space the fourth physical domain of operations alongside land, sea and air, accelerate preparations for space warfare, and deter and contain potential adversaries.

Analysts believe Japan's military preparations and activities in space will continue to expand.

First, Japan's space forces could likely use advanced sensors and other technologies to track and identify other countries' spacecraft and satellites in orbit, laying the groundwork for future operations, either independently or in coordination with the Maritime Self-Defense Force and other military forces, against orbital targets.

Second, Japan could use reconnaissance satellites to provide target information for long-range strike systems, including military aircraft, warships and cruise missiles.

Third, such capabilities could provide strong communications support for Japanese naval and air forces conducting overseas and long-range operations.

To ease domestic and international opposition, the Japanese government has claimed that the mission of the space operations command is to protect space infrastructure that supports daily life. However, such claims are merely an attempt to disguise its true intentions.

The space operations command covers functions including space situational awareness, satellite interference monitoring and space-based intelligence analysis. Japan's developing commercial space technologies could also be directly applied to counter-satellite operations, including satellite interference, on-orbit disruption and even the destruction of spacecraft. Therefore, Japan's development of space warfare capabilities is not driven by defensive needs, but is aimed at preparing for space operations as well as maritime and overseas military operations.

Japan's unchecked development of space warfare capabilities will inevitably accelerate the weaponization and militarization of outer space and fuel a space arms race. The move also evokes concerns stemming from Japan's militarist past, and raises fears that a "Pearl Harbor incident" in space could happen. The international community needs to remain highly vigilant against Japan's military expansion into space.

Zhang Junshe is a military affairs expert.