JMSDF Strengthens Foothold in Nansei Islands as Taiwan Crisis Looms

Japan Forward

20-05-2025

Port calls by Japan Maritime Self-Defense Force (JMSDF) vessels at Ishigaki Port in Okinawa Prefecture have risen sharply in recent years. By April 2025, a range of ships — including training support vessels, escort ships, minesweepers, and mother ships for underwater disposal teams — had already made stops at the port.
In 2024, the JMSDF's largest ship, the Izumo , anchored off the coast of Ishigaki Island. The United States Navy has likewise maintained a steady presence, dispatching vessels roughly once a year. With tensions over a potential Taiwan contingency on the rise, Ishigaki Port has effectively become a forward operating base for both Japanese and American naval forces. Their presence serves as a tangible demonstration of strengthened deterrence.
While the Japanese government refrains from making overt declarations, it continues to quietly enhance the Self-Defense Forces' readiness. These efforts are aimed at strengthening deterrence in anticipation of a crisis in the Taiwan Strait.
Since fiscal 2024, Ishigaki Port has been designated a Specified Use Port. This status creates a framework that facilitates smoother berthing and logistical operations for both the Japan Self-Defense Forces (JSDF) and the Japan Coast Guard (JCG).
Soon after the designation, in late August 2024, the Izumo sailed to waters near Okinawa following joint exercises with European naval vessels and anchored offshore from Ishigaki Island. The ship was opened for public viewing by members of the local defense association and selected citizens. A Japan Coast Guard patrol vessel (foreground) sails alongside a China Coast Guard ship. (Photo courtesy of the Japan Coast Guard)
In February 2025, as the fiscal year drew to a close, the US Navy's amphibious transport dock USS San Diego made a port call at Ishigaki. That, too, was opened to the media. The year before, a US Aegis destroyer made a similar visit.
Meanwhile, China has stepped up its military activity in the region. It has been staging large-scale exercises around Taiwan and Okinawa that simulate a maritime blockade of Taiwan. These drills involve a range of assets, including multiple warships, drones, and even aircraft carriers. Beijing has taken a particularly hostile stance toward Taiwanese President Lai Ching-te, who assumed office in January 2024.
Ishigaki City plans to launch a regular ferry route to Taiwan by September 2025. While Ishigaki Port already serves as the home base for the Japan Coast Guard's dedicated Senkaku patrol unit, it is set to play an even more critical role in safeguarding maritime routes to Taiwan.
In the event of a Taiwan contingency, commercial navigation in the surrounding waters would likely face significant disruption. Rising concerns include the possibility of China deploying naval mines to enforce a blockade.
The JMSDF minesweeper Kuroshima , which called at Ishigaki in May, is specifically tasked with mine-clearing operations. Another vessel, the mother ship for underwater disposal teams, departed the port on April 29 and serves as a mobile base for specialized underwater personnel. Both ships are based in Okinawa's main island and visited Ishigaki at roughly the same time in 2024. The presence of the JMSDF is becoming increasingly prominent alongside that of the Coast Guard.
In an interview, Hiroaki Yonemori, Chairman of the Yaeyama Defense Association, spoke about ongoing efforts to attract more JMSDF vessels to the islands. Anticipating further increases in port calls, he stressed the need for robust wharf infrastructure to accommodate the growing traffic.
(Read the article in Japanese .)
Author: The Sankei Shimbun