Japan's F-35B stealth fighters signal end of post-war military restraint
Constitutional engineering and strategic transformation drive Tokyo's most significant military modernisation since 1945
The arrival of Japan's first F-35B Lightning II stealth fighters in August marks more than routine aircraft delivery. These three jets, photographed refuelling in Hawaii en route to Nyutabaru Air Base, represent Japan's most significant military transformation since 1945—a carefully orchestrated departure from purely defensive capabilities that challenges decades of constitutional restraint.
Japan's acquisition of 42 F-35B short take-off and vertical landing fighters, valued at $23.11 billion as part of a broader defence modernisation programme, signals Tokyo's evolution from reactive defender to active regional power. Unlike conventional F-35As that require full runways, these variants can operate from Japan's converted aircraft carriers—ships still diplomatically termed "multi-purpose operation destroyers" to maintain constitutional plausibility.
Constitutional choreography meets strategic necessity
Japan's approach exemplifies sophisticated constitutional engineering. The Maritime Self-Defence Force's Izumo-class vessels undergo "modifications" rather than "conversion" to accommodate fixed-wing aircraft. Defence Minister Gen Nakatani carefully describes enhanced "defensive capabilities" whilst systematically building power projection assets that extend Japan's reach hundreds of miles beyond its shores.
This linguistic precision matters politically. Article 9 of Japan's constitution prohibits maintaining "war potential," forcing creative interpretations as security threats intensify. The 2014 reinterpretation allowing "collective self-defence" provided legal foundation, but public opinion remains sensitive to militaristic overtones. Hence "helicopter destroyers" become "multi-purpose operation destroyers" whilst gaining genuine aircraft carrier capabilities.
The F-35B programme demonstrates this constitutional choreography in action. Rather than building new aircraft carriers—politically impossible—Japan modifies existing vessels with heat-resistant deck coatings, reinforced flight decks, and precision landing systems. The JS Kaga completed its first successful F-35B operations off California in October, proving the concept whilst maintaining diplomatic deniability.
Industrial strategy as alliance leverage
Japan's F-35 programme reveals sophisticated strategic thinking beyond simple procurement. The £147 billion commitment encompasses 105 F-35A conventional fighters and 42 F-35B variants, making Japan the programme's second-largest customer after America. This scale provides both technological access and alliance leverage whilst building domestic industrial capabilities.
Significantly, Japan maintains the final assembly and check-out facility in Nagoya for F-35A production, creating technological integration with American supply chains. However, F-35Bs are manufactured exclusively at Lockheed Martin's Fort Worth facility, ensuring continued American involvement in Japan's most sensitive military capabilities. This deliberate dependence strengthens alliance bonds whilst providing technology transfer opportunities.
The industrial arrangement reflects Japan's broader defence strategy: deep integration with American capabilities to ensure security guarantees whilst building indigenous expertise for eventual independence. Japan's parallel development of the Global Combat Air Programme with Britain and Italy demonstrates this dual approach—alliance dependence in the near term, technological sovereignty as the ultimate goal.
Geographic strategy meets regional pressure
The F-35B deployment plan reveals careful strategic positioning. Rather than dispersing aircraft across multiple bases, Japan concentrates initial operations at Nyutabaru Air Base in Kyushu, strategically located near the Kaga's home port at Kure. This proximity enables rapid deployment to contested areas, particularly around the Senkaku Islands where Chinese pressure intensifies.
Chinese coast guard vessels now maintain presence around the Senkakus for over 330 days annually, fundamentally altering the territorial status quo through persistent encroachment. The Maritime and Aerial Communication Mechanism, established in 2018 to prevent incidents, covers only defence authorities—leaving tactical-level confrontations unaddressed. Recent incidents involving Chinese vessels pursuing Japanese fishing boats within territorial waters demonstrate escalating assertiveness.
Japan's F-35B capability provides multiple response options to this grey-zone pressure. The aircraft's 450-nautical-mile combat radius from either land bases or carrier platforms enables surveillance and rapid response across the East China Sea. More importantly, the psychological impact of genuine air power projection alters Chinese calculations about contested areas.
The broader Southwest Islands defence strategy incorporates F-35B capabilities into a comprehensive deterrent framework. Japan deploys anti-ship missiles throughout the island chain, develops hypersonic weapons for 2026 deployment, and enhances radar coverage from Yonaguni to the main islands. F-35Bs provide the mobile strike capability that makes this island-based strategy credible.
Strategic implications beyond aircraft
Japan's F-35B programme represents more than military modernisation—it signals fundamental strategic reorientation. For seven decades, Japan maintained deliberately limited military capabilities to reassure neighbours and focus on economic development. That paradigm now yields to security imperatives as regional power balances shift dramatically.
China's military expansion drives much of this recalculation. The People's Liberation Army's modernisation targets American military dominance whilst building capabilities that could overwhelm Japanese defences through sheer scale. Japan cannot match Chinese shipbuilding or manpower, but F-35B deployment from distributed platforms complicates Chinese planning whilst maintaining alliance interoperability.
The programme also reflects changing domestic attitudes towards defence spending. Japan's 2025 defence budget reaches $55.1 billion, representing 13 consecutive annual increases as threat perceptions solidify. Public support for enhanced capabilities grows as Chinese assertiveness around the Senkakus demonstrates the inadequacy of purely diplomatic responses.
Internationally, Japan's military modernisation encourages allied coordination whilst potentially concerning some regional partners. The October 2024 joint exercises involving British carrier HMS Queen Elizabeth, Italian carrier Cavour, and Japanese forces around Okinawa demonstrate growing multilateral cooperation. However, South Korea remains sensitive to Japanese military expansion given historical grievances.
Future trajectory and implications
The F-35B programme's strategic significance extends beyond current deployments. Japan plans to operate these aircraft from both land bases and converted carriers, providing flexibility unavailable to conventional forces. The Izumo's modifications complete in 2027 with the Kaga following in 2028, creating genuine expeditionary capabilities.
This transformation occurs amid accelerating regional tensions. China's activities around Taiwan intensify whilst North Korean missile capabilities advance rapidly. Russia's renewed aggression following Ukraine demonstrates that great power competition extends to Asia-Pacific dynamics. Japan's F-35B capability provides deterrent assets relevant to multiple threat scenarios.
The programme's success depends partly on personnel development. Japan establishes a temporary F-35B squadron at Nyutabaru with approximately 110 personnel, building expertise through American training partnerships. The Japan Air Self-Defence Force, rather than maritime forces, operates these aircraft—reflecting Japan's preference for unified command structures over service rivalries.
Looking ahead, Japan's F-35B deployment represents the leading edge of broader military transformation. The programme validates concepts for operating advanced aircraft from austere platforms whilst maintaining alliance interoperability. Success here informs future decisions about additional capabilities, including long-range strike systems and enhanced missile defences.
Japan's careful navigation of constitutional constraints whilst building genuine military capabilities offers lessons for other democracies facing authoritarian pressure. The F-35B programme demonstrates that strategic transformation remains possible within legal frameworks, provided sufficient political will and careful implementation.
The three stealth fighters delivered to Nyutabaru Air Base in August represent more than technical capability—they symbolise Japan's measured but determined response to a changing security environment. As Chinese assertiveness grows and American alliance commitments face scrutiny, Japan's F-35B programme ensures that one of Asia's most important democracies possesses the military capabilities necessary for deterrence and, if required, defence of its interests and values.