Japan Issues Space Domain Defense Guidelines to Enhance National Security in Orbit

Japan has formally recognised outer space as a critical operational domain alongside land, sea, and air, with the Ministry of Defense (MOD) publishing its new Space Domain Defense Guidelines on 7 August 2025. Formulated on 28 July, the document sets the strategic direction for strengthening the country’s ability to operate, defend, and exploit space-based assets. The guidelines acknowledge the increasing reliance of Japan’s economy, society, and disaster response capabilities on satellite services such as communications, observation, and Position, Navigation and Timing (PNT). They also highlight how space is becoming a contested environment, with major powers—particularly China and Russia—developing capabilities for reconnaissance, long-range precision strike support, and anti-satellite (ASAT) operations. Drawing on lessons from the war in Ukraine, where commercial imagery and satellite communications had a significant military impact, the MOD emphasises that Japan must ensure secure, continuous use of space for both governmental and private-sector needs, even under hostile conditions.