The U.S. Navy's Foreign-Built Escort Ship Ban Lifted: The Mogami-Class Frigate as a Litmus Test for 2026

What caught my attention most in the White House memorandum dated August 13 was a passage that ordered the demonstration of a new surface combatant capable of anti-submarine, anti-surface, and convoy escort operations within 90 days, rather than the debate over the CVN-81's steam catapult. The first two ships are to be built at foreign shipyards, after which mass production will shift to domestic investment and technology transfer as conditions. This condition appears to be a stopgap measure to fill the U.S. Navy's shortfall, but in reality, it is a system design that tests how far the industrial base of the U.S.-Japan alliance can be connected.

Changed Evaluation Criteria in 90 Days

According to White House materials, the new approach emphasizes using a mature parent design as modeled after Finland's icebreaker procurement. There are three key points. First, what the U.S. side dislikes is not the new design itself, but the cumulative design changes that NAVSEA has repeated over the years. Second, foreign companies must either establish new shipyards in the U.S. or invest in existing facilities. Third, not only construction but also parts supply and maintenance must be localized in the U.S. In other words, candidate ships must possess not only performance but also a reproducible production method.

Reasons the Mogami-Class is a Candidate

The Mogami-class, including the "Natori" delivered by Mitsubishi Heavy Industries in May, has a total length of 130 meters, a full-load displacement of about 5,500 tons, a speed exceeding 30 knots, and the capability to operate SH-60 patrol helicopters, as well as facilities for launching and recovering unmanned surface vessels and unmanned submarines. The ability to seamlessly integrate anti-submarine and anti-surface capabilities within a single hull, along with a premise of small crew operations, aligns well with the U.S. Navy's urgent need for escort missions. The emergence of the Japanese proposal in the competition for surface combatants for Australia also indicates that the export suitability of the design cannot be completely dismissed.

However, optimism should be avoided here. What the U.S. truly desires is not "excellent escort ships made in Japan," but an industrial package that can be continuously built domestically. The Mogami-class was developed in response to the Japan Maritime Self-Defense Force's requirements, but it does not directly fit into the U.S. Navy's combat systems, supply standards, damage control manuals, or repair responsibilities. It is significant that the memorandum explicitly states the suppression of modifications to the parent design, but whether the U.S. Navy can truly endure this until the end is another matter. If demands for modifications swell here, the superiority of the Japanese proposal will quickly diminish.

The Real Challenge for Japan

From Japan's perspective, the core of this discussion is not export performance, but how much production leadership can be maintained. The shipbuilding crisis in the U.S. is a reality, and the recovery of the U.S. fleet is beneficial for Japan in countering the quantitative expansion of the Chinese Navy. However, the more domestic investment progresses, the more Japan's shipbuilding capacity itself risks becoming hollow, which would be counterproductive. In my view, the true challenge lies not in the superiority of the ships, but in how quickly the U.S. and Japan can make political decisions for joint production while suppressing design changes. Ships that protect SLOCs only have meaning once they are at sea. Even if they are excellent on paper, if decision-making for construction is delayed, the gaps in the alliance will not be filled.