U.S. Air Force and Navy aircraft line up on the runway during an elephant walk at Kadena Air Base, Japan, Nov. 21, 2023. (U.S. Air Force photo by Airman 1st Class Tylir Meyer)

WASHINGTON — The Pentagon today announced a new plan for its fighter jet posture in Japan, which would broadly see older US Air Force F-15s and F-16s replaced by newer aircraft like the F-15EX and F-35, as well as changes involving Marine Corps F-35Bs.

“The modernization plan, which will be implemented over the next several years, reflects over $10 billion of capability investments to enhance the U.S.-Japan Alliance, bolster regional deterrence, and strengthen peace and stability in the Indo-Pacific region,” according to the DoD announcement, which was released at midnight Tokyo time.

One of the biggest changes, anticipated since the Air Force announced a plan to withdraw F-15C/D aircraft beginning in 2022, would see Kadena Air Base’s 48 F-15s replaced by 36 F-15EXs, according to the Pentagon announcement. Located on Okinawa near the southern tip of the Japanese archipelago, Kadena, sometimes called the “Keystone of the Pacific,” is the closest US military air base to the island nation of Taiwan and a critical site for the defense of Japan, making it a strategic priority.

The Air Force has been rotating fourth- and fifth-generation fighters through Kadena to maintain its presence at the base as F-15 aircraft were gradually removed, a temporary approach that previously drew criticism from GOP lawmakers. The rotation will continue throughout the transition to the F-15EX, according to the DoD announcement, though no timelines for any recapitalization efforts were provided. 

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Alongside the Kadena revamp, the Air Force will additionally modernize aircraft at Misawa Air Base, which would entail an “upgrade” from 36 F-16s to 48 F-35As. Misawa is located in the north of the largest Japanese island of Honshu. 

Lastly, the Pentagon will “modify” the amount of F-35B stealth fighters at Marine Corps Air Station Iwakuni, located in the south of Honshu, “to support the service’s force design modernization implementation.” The Marine Corps will continue “an enduring and rotational aircraft presence” at the installation, the announcement says, though no further information was provided. 

The modernization plan is likely welcome news for defense hawks eager to see the US strengthen its deterrent posture in the region as Beijing eyes a military operation to seize Taiwan — though the lack of one-for-one replacements at Kadena may also invite scrutiny from interested parties. As part of a broader Indo-Pacific strategy, the US has gained access to new bases in places like the Philippines while also deepening relationships, including by codeveloping advanced technologies, with regional allies like Japan and Australia

“The Department’s plan to station the Joint Force’s most advanced tactical aircraft in Japan demonstrates the ironclad U.S. commitment to the defense of Japan and both countries’ shared vision of a free and open Indo-Pacific region,” the DoD said.