🇯🇵 JAPAN STABILITY INDEX

Japan's Self-Defense Forces (JSDF) are undergoing the most significant expansion since the post-WWII pacifist constitution was adopted, driven by deteriorating regional security.

Key Developments:

• Defense Budget: Japan committed to doubling defense spending to 2% of GDP by 2027 (from ~1%); one of the largest peacetime military buildups globally
• Counterstrike Capability: Japan acquiring Tomahawk cruise missiles and developing indigenous long-range strike weapons to target enemy missile sites
• National Security Strategy: 2022 NSS identified China as an "unprecedented strategic challenge" and North Korea as an "existential threat"
• Izumo Conversion: Helicopter destroyers being converted to operate F-35B aircraft — Japan's first de facto aircraft carriers since WWII
• Space & Cyber: Established Space Operations Squadron; expanding cyber defense capabilities

North Korea's missile program poses the most direct near-term military threat to Japan, with ballistic missiles routinely flying over or near Japanese territory.

Threat Profile:

• Overflight Incidents: Multiple North Korean missiles have flown over Japanese territory, triggering J-Alert emergency notifications to civilians
• ICBM Development: Hwasong-17 and Hwasong-18 ICBMs can reach the U.S. mainland; Hwasong-15 range covers all of Japan
• Theater Missiles: Nodong and Scud-ER variants can target all of Japan; deployed in mobile launchers for survivability
• BMD: Japan operates PAC-3 and SM-3 missile defense systems; BMD ships (Kongo class) positioned to intercept
• Nuclear Dimension: North Korea is assessed to have sufficient fissile material for 40-50 nuclear warheads

China's maritime pressure on Japan has intensified through China Coast Guard and PLAN vessel incursions near the Senkaku/Diaoyu Islands and increasingly assertive air operations.

Key Issues:

• Senkaku Islands: Japan administers; China claims as Diaoyu; China Coast Guard vessels enter Japanese territorial waters with increasing frequency
• ADIZ Violations: PLA aircraft regularly intrude into Japan's ADIZ; Japan scrambled fighters 722 times in FY2023 — a record
• Naval Transits: PLAN vessels transit Tsugaru, Osumi, and Miyako Straits with increasing frequency, testing Japanese response
• Submarine Activity: PLAN submarines tracked in waters around Japan; Japan's ASW capabilities being upgraded
• Joint China-Russia: Combined Chinese-Russian naval patrols near Japanese waters represent a new challenge

The U.S.-Japan alliance is the cornerstone of Indo-Pacific security, currently being modernized for the most significant transformation in decades.

Alliance Developments:

• Command Integration: U.S. and Japan integrating operational command structures; U.S. Forces Japan being upgraded to a Joint Force Headquarters
• Base Access: U.S. maintains ~50,000 troops in Japan; Okinawa hosts critical bases including Kadena AFB; basing costs shared
• Amphibious: Japan establishing Marine amphibious units for island defense; coordinating with U.S. Marine Corps
• South Korea: Japan-South Korea relations improved under Kishida/Yoon; Camp David trilateral (2023); intelligence sharing expanded
• AUKUS & Partners: Japan designated "associate member" for AUKUS Pillar 2 (advanced capabilities)