Japan is ramping up efforts to establish a strong foothold for its Self-Defense Forces’ amphibious operations in Sasebo City, Nagasaki Prefecture of Kyushu, the southernmost of the nation’s four main islands, with China’s increasingly assertive maritime expansion in mind.
Specifically, the Ministry of Defense in Tokyo plans to build a system for joint operations between the Ground Self-Defense Force (GSDF)’s existing Amphibious Rapid Deployment Brigade, which is headquartered in Sasebo, and the Maritime Self-Defense Force (MSDF)’s Amphibious and Mine Warfare Group (a tentative name given by the Defense Ministry) that will be newly organized in the city by March 2026.
This move aims to bolster capabilities to defend and recapture remote islands, especially in Japan’s southwestern Nansei island chain, which spans about 1,200 km from Kagoshima to Okinawa, stretching southwest toward Taiwan. The chain includes the disputed Senkaku/Diaoyu Islands in the East China Sea. The islands are controlled by Japan but also claimed by China and Taiwan.
The plan came as part of the largest-ever organizational restructuring in the history of the MSDF, which will abolish its existing Fleet Escort Force and the Mine Warfare Force, and then consolidate them into a new “Fleet Surface Force” (tentative name) in order to centralize the operation of the MSDF’s surface vessels by the end of fiscal year 2025.
“This is a complete scrap-and-build reorganization of our surface vessel fleet,” an MSDF spokesperson said.
A diagram from a Japan Ministry of Defense document explaining the reorganization of the MSDF. In order to establish a system for unifying the command and supervision of the entire surface fleet – consisting of the existing four Escort Flotillas, the five Escort Divisions, and the Mine Warfare Force – a new “Fleet Surface Force” will be established by the end of fiscal year 2025.
The MSDF currently has four Escort Flotillas, with headquarters at Yokosuka of Kanagawa Prefecture, Sasebo of Nagasaki Prefecture, Maizuru of Kyoto Prefecture, and Kure of Hiroshima Prefecture. Under the new reorganization plan, these four flotillas will be transformed into three Surface Warfare Groups (tentative name) under the Fleet Surface Force.
This means that one of these four Escort Flotillas’ command headquarters will be eliminated. According to a press briefing on the proposed fiscal 2025 defense budget held by the Ministry of Defense in late December, the existing HQ in Sasebo will be retired in the reorganization – but Sasebo will take on another important role.
Defense officials said the headquarters of the Fleet Surface Force will be located in Yokosuka. Under this force, the headquarters of the first Surface Warfare Group will be located in Yokosuka, the second Surface Warfare Group in Kure, the third Surface Warfare Group in Maizuru. And they said that in Sasebo, the command headquarters of the new Amphibious and Mine Warfare Group will be established.
This new Amphibious and Mine Warfare Group will merge the existing Mine Warfare Force with transport and amphibious ships to support mine warfare and amphibious warfare operations.
The Defense Ministry was allocated 25.5 billion yen ($161.7 million) to construct MSDF facilities in the Sakibe-East District of Sasebo for fiscal year 2025. Once construction is complete, the MSDF will have a large wharf capable of mooring the Osumi-class tank landing ships and the MSDF’s largest ships, the Izumo-class destroyers. The ministry expects to moor those large naval vessels in Sasebo starting in fiscal year 2029.
Each of the MSDF’s current four escort flotillas consist of one helicopter destroyer (DDH), five general-purpose destroyers (DD), and two Aegis destroyers (DDG) for a total of eight vessels. Currently, the second Hyuga-class helicopter destroyer, JS Ise, is homeported at the MSDF’s Sasebo Base and is scheduled to remain deployed to the new Amphibious Mine and Warfare Group there.
“The current Mine Warfare Force, which will be transformed into the Amphibious and Mine Warfare Group soon, has made very effective use of the DDHs if we look at its track record and training,” Admiral Saito Akira, chief of staff of the MSDF, said at a press conference on September 3 last year.
“It is true that the Mine Warfare Force could be commanded and controlled by transport ships, but communication capabilities and space on those ships are limited, so one of the four DDHs has been dispatched to the Mine Warfare Force to carry out operations, training, and exercises. Therefore, based on that track record, we will deploy one of the four DDHs to the new Amphibious and Mine Warfare Group,” Saito continued.
Meanwhile, the GSDF’s Amphibious Rapid Deployment Brigade, which was established in March 2018, is headquartered at Camp Ainoura in Sasebo. Two Amphibious Rapid Deployment Regiments (each 600 personnel) are based at the same camp. In March 2024, the third Amphibious Rapid Deployment Regiment was established at Camp Takematsu in Omura City, also in Nagasaki Prefecture.
In the event of an emergency, their main mission is to recapture occupied islands. The brigade mainly lands from the sea using amphibious vehicles and boats to launch battles. Thus, the brigade has been often described by the media as a “Japanese version of Marines” in reference to the U.S. Marine Corps, which is responsible for amphibious operations.
In addition, it should not be forgotten that part of the Expeditionary Strike Group 7 is located in Sasebo. It is the U.S. Navy’s only forward-deployed amphibious force and is headquartered at White Beach Naval Facility, Okinawa, with an operating detachment in Sasebo. Its subordinate Amphibious Squadron (PHIBRON) 11 and Mine Countermeasures Squadron (MCMRON) 7 are also based at the U.S. Navy’s Sasebo Base.
The essence of amphibious warfare is joint operations, and close cooperation between the GSDF, the U.S. Navy, and the MSDF in Sasebo will be required more than ever before.