Japan has officially begun deploying its F-35B Lightning II stealth fighters as part of a high-profile exercise in the Philippine Sea. This deployment, the first operational use of Japan’s short takeoff and vertical landing (STOVL) variant of the fifth-generation jet, marks a major turning point in the nation’s postwar defense strategy, with implications far beyond its immediate geography.
The F-35B, manufactured by U.S. defense giant Lockheed Martin, is the only stealth fighter in the world with STOVL capability—allowing it to operate from short or improvised runways, including roads, island bases, and specially modified naval platforms. It combines stealth characteristics, advanced electronic warfare capabilities, supersonic performance, and unparalleled sensor fusion, making it ideal for joint and expeditionary operations in contested environments.
Unlike its conventional counterpart, the F-35A, the F-35B utilizes a patented Shaft-Driven LiftFan system that allows it to perform vertical landings and short takeoffs. This makes it especially useful for navies or air forces with limited access to long runways or full-sized aircraft carriers. With a combat radius of over 800 km, a top speed of Mach 1.6, and an internal weapons payload of 6,800 kilograms, the F-35B offers tactical flexibility and survivability in frontline missions.
It also features the AN/APG-81 AESA radar, the AN/ASQ-239 electronic warfare suite, and a Distributed Aperture System (DAS), enabling full spherical sensor coverage, shared targeting, and secure data links with allied forces. These characteristics make the F-35B not merely a fighter jet, but a node in a broader combat network.
Japan’s acquisition of 42 F-35B fighters is part of its 2018 defense modernization program, aimed at reshaping the Japanese Self-Defense Forces (JSDF) into a more agile, mobile, and interoperable force. As of mid-2024, 18 of these aircraft have become operational, with four currently based at Nyutabaru Air Base in Miyazaki Prefecture.
On August 7, 2025, these aircraft will begin forward deployments to support patrol and deterrence missions across the Nansei Islands chain—a string of Japanese islands stretching toward Taiwan that has become increasingly volatile due to near-daily incursions by Chinese surveillance aircraft and fighters. Operating in this region provides a testbed for Japan’s new approach: to blend land- and sea-based aviation into a seamless, survivable strike network.
Crucially, the F-35B enables the reintroduction of fixed-wing naval aviation into Japan’s force structure—an historic pivot not seen since the Imperial Japanese Navy’s disbandment after World War II. The modified Izumo-class helicopter destroyers, JS Izumo and JS Kaga, are now fully STOVL-capable, enabling Japan to project air power from the sea for the first time in nearly 80 years.
The timing of Japan’s deployment coincides with Operation Highmast, a high-profile multinational carrier strike mission led by the United Kingdom’s HMS Prince of Wales—currently the flagship of Carrier Strike Group 25 (CSG25). The UK has deployed 18 of its own F-35Bs aboard the carrier, which has been crisscrossing the Indo-Pacific since April.
CSG25, under the command of Commodore James Blackmore, includes over 2,500 military personnel from the UK, Norway, Spain, and Canada. The British carrier is accompanied by the Canadian frigate Ville de Québec, the Spanish frigate Méndez Núñez, the Norwegian frigate Roald Amundsen, and the British destroyer HMS Dauntless. The group’s mission spans the Mediterranean, Middle East, and Pacific Rim, reaffirming NATO’s strategic presence and engagement in the Indo-Pacific region.
The Japanese JS Kaga, now operating alongside HMS Prince of Wales in the Philippine Sea, has also begun joint drills. These include cross-deck F-35B operations, refueling procedures, and live flight integration between British and Japanese naval aviation personnel. Japanese pilots—many of whom are still in training with U.S. Marine Corps instructors—are expected to participate as observers in these launch and recovery missions, gaining essential knowledge on sea-based STOVL operations.
While the UK and Japan draw closer in air-sea integration, the United States is the connective tissue in this trilateral cooperation. U.S. Marine Corps squadron VMFA-242, stationed in Japan, has previously hosted Japanese pilots for F-35B training. Recently, U.S. F-35Bs were deployed aboard HMS Prince of Wales, continuing a now-routine practice of interoperability between the U.S. and allied navies operating the Lightning II.
At the same time, three British F-35Bs have been detached to South Korea under Operation Hightower, an allied airpower initiative designed to test rapid deployment and joint readiness across the Korean Peninsula and surrounding waters. This overlapping of operations—Highmast in the South Pacific, Hightower in Northeast Asia—demonstrates a coordinated strategy among allies to challenge growing Chinese military assertiveness in multiple theaters simultaneously.
China’s expanding presence around Taiwan, the East China Sea, and the South China Sea has accelerated regional defense initiatives. Frequent Chinese military overflights of Japan’s southwestern islands and aggressive maneuvers in the Taiwan Strait have prompted Tokyo to adopt a more outward-facing and proactive defense strategy.
The F-35B, with its ability to operate from remote islands, short airstrips, and helicopter carriers, fits squarely into this vision. It enables Japan to disperse its combat air power across the archipelago and project deterrence far beyond its home islands. Moreover, with allied support from the UK and U.S., these capabilities form the backbone of a resilient, interconnected regional security framework.
Japan’s updated National Security Strategy (NSS), released in late 2022, formalized this shift, authorizing counter-strike capabilities and the forward basing of long-range missiles and fighter jets. The F-35B now provides the means to act on that policy—offering precision strike options, electronic warfare dominance, and survivability in a maritime-heavy theater.
While this is Japan’s first operational deployment of the F-35B, it is far from the last. The JS Izumo and JS Kaga are both expected to complete their full STOVL carrier conversions by 2028. This timeline coincides with the expected delivery of the remaining 24 F-35Bs, culminating in a two-carrier naval aviation capability not seen in East Asia outside China and the U.S.
Japan’s long-term goal appears to be the creation of a mobile sea-air deterrence force, capable of responding to crises in Taiwan, the East China Sea, or the wider Indo-Pacific. Operating F-35Bs from Izumo-class carriers gives Japan not only defense-in-depth for its southern islands but also expeditionary reach—the ability to support allies, enforce air denial zones, or contribute to multinational naval patrols.
This aligns with broader alliance goals: enhancing interoperability, burden-sharing, and power projection without relying entirely on the U.S. military. It also deepens Japan’s defense ties with partners like the UK and Italy—both of which operate F-35Bs and have demonstrated interest in joint training, operations, and eventual participation in Japan’s future fighter program, the GCAP (Global Combat Air Programme).
From a historical standpoint, Japan’s use of aircraft carriers to launch fixed-wing combat aircraft is deeply symbolic. For over 75 years, Japan avoided carrier-based aviation due to both constitutional constraints and the legacy of its World War II-era navy. The F-35B changes that calculus.
This is not a revival of imperial ambitions but rather a calculated adaptation to a transformed security environment. China’s military buildup, North Korea’s provocations, and growing uncertainty over U.S. long-term commitments have all contributed to Tokyo’s shift toward greater self-reliance and allied burden-sharing.
The Japanese public, once firmly pacifist, has also shifted—slowly but noticeably—toward accepting a more assertive defense posture. Polling shows increased support for investments in missile defense, naval aviation, and alliance cooperation.
