Keen Sword, the largest U.S.-Japan biennial joint drill, will feature two key systems of the Marine Corps’ littoral force: the anti-ship NMESIS (Navy-Marine Expeditionary Ship Interdiction System) and air-defense MADIS (Marine Air Defense Integrated System).

Yonaguni’s local government disclosed the deployment on Friday, a day after the Okinawa Defense Bureau relayed deployment plans on Oct. 1.

The systems will be deployed to Yonaguni for the first time, as this year’s iteration shifts to ground-based, multi-island, sea-denial operations aimed at distributing American and Japanese forces across the southwestern islands.

The deployment also reflects a broader shift by the United States and Japan toward mobile missile and air-defense systems that can operate from scattered islands.

NMESIS and MADIS form the cornerstone of the U.S. Marine Corps’ force design modernization and restructuring plan, which moves away from heavy armored platforms to focus on small-unit, expeditionary forces that can capture and defend islands.

NMESIS can strike targets at around 115 miles and could threaten ships operating in waters around Taiwan. The reported deployment, in turn, has drawn criticism from Chinese military experts even while China’s PLA Navy and coast guard vessels have increased activities around Taiwan.

The NMESIS and MADIS systems first arrived with the Okinawa-based 12th Marine Littoral Regiment 3rd Marine Division in June. The units were earlier deployed to the Philippines’ northern Batanes Islands and western Laoag province during the Balikatan drills.

The deployment comes as Japan tests what defense officials describe as standoff-strike capabilities, missile systems that can strike targets far from enemy weapons, while strengthening its southwestern islands for distributed military operations.

According to the Ministry of Defense, troops from nine countries, including the Australian and French armies, will join 45,000 Japanese Self-Defense Forces personnel for this year’s exercise, which will run from Oct. 19 to 29.

The exercise will also bring together a number of U.S. and Japanese ground-based missile systems.

The U.S. Army will deploy HIMARS (High Mobility Artillery Rocket Systems) weapons to Camp Ishigaki, some 80 miles from Yonaguni.

The Army’s Typhon missile launcher will also be moved to Okinawa mid-month, although no disclosures have been made about whether the mid-range system will be used for the exercise.

In past iterations of the drill, the USS George Washington joined the exercises, but the carrier strike group was sent to the Arabian Sea in August to replace the USS Abraham Lincoln, which was returning home after a prolonged deployment.

That prominent naval absence is expected to emphasize the exercise scenario shift toward a land-based network of mobile systems.

Last year, exercises in Yonaguni focused on maximizing the island as a forward operating base. This year, Keen Sword will showcase the Ground Self-Defense Force’s three anti-ship missile systems, which are the core of Japan’s long-range standoff-strike capabilities.

The JGSDF will train with the new ground-launched Type-25 surface-to-ship guided missile system, formerly known as the upgraded Type-12, which was fielded across the Nansei Islands in late March. The Type-25 SSM has a strike reach of 1,000 kilometers.

The lineup also includes the Type-88 ground-to-ship missile and the upgraded Type 03 Chu-SAM Kai medium-range ground-to-air guided missile.

Keen Sword was originally planned as a much larger exercise, local government officials said, but opposition forced the ministry to scale it down to its current iteration.

Yonaguni is Japan’s last inhabited island in the Nansei, a chain of scattered islands in southwestern Okinawa and a fast-emerging flashpoint amid rising tensions around Taiwan.

The JGSDF set up a radar and surveillance system on the island in 2016 to fill a “surveillance vacuum” in the seascapes stretching from the island to Taiwan, according to officials.

The island has seen increased joint exercises between Japanese and U.S. troops while it faces incursions from Chinese ships.

In June this year, the government reported incursions by Chinese Coast Guard ships encroaching on Japan’s exclusive economic zone between Yonaguni and Taiwan. In 2022, China’s ballistic missile landed just 80 kilometers from the island.

While tensions surround the island, local officials have raised concerns about the use of civilian roads, ports, and airways.

Large equipment for the exercise will be transported by sea through Kubura Port, and local authorities have asked residents to avoid using roads during the movement of military equipment.

There are also concerns after a Japan Self-Defense Forces V-22 Osprey was involved in a ground-strike incident in the same exercise in 2024. The incident prompted then-defense minister Gen Nakatani to order the grounding of Japan’s 17 Osprey aircraft.

This year, however, the V-22 Osprey will not participate, Yonaguni Mayor Tsuneo Uechi told Mainichi Shimbun on Oct. 2.

While the island understands the need for military training, Uechi said it is not ready for large-scale exercises that exceed the island’s capacity. The local government remains opposed to the exercises and continues to hold talks with the defense ministry.

This development marks a key shift in the country’s defense strategy. Japan committed to acquiring 400 Tomahawks last year to equip its eight Aegis destroyers as part of a larger standoff capability, which includes fielding upgraded Type 12 missiles in the southwest and deploying hyper velocity gliding projectile systems across the country.

The existing missile defense network may not be fully capable of responding to threats, Defense Minister Shinjiro Koizumi told reporters in a briefing on Friday.

“To prevent missiles flying through the missile defense network and to prevent further armed attacks, it is necessary to … have the ability to counterattack. Stand-off missiles can also be used for this counterattack ability,” Koizumi said.

The destroyer’s launcher modification marks a landmark milestone in the country’s efforts to rapidly deploy stand-off capabilities and bolster deterrence measures, he added.

Stand-off weaponry describes a class of arms with ranges so long that operators can fire them from a safe distance, without fearing countermeasures capable of reaching them.

The defense ministry introduced stand-off capabilities in 2017, and it formed the core of the security strategy shift in 2020, which later expanded to additional policy documents, including a detailed buildup plan in the country’s southwest in 2022.

The Tomahawk cruise missiles can be launched from ships or submarines with a range of over 1,600km. The Japanese variant can be rerouted during flight, and advanced versions are capable of hitting moving targets.

The refitted JS Chokai can load and fire both the Block IV and V variants of the cruise missiles.

JS Chokai arrived at Naval Base San Diego, California, in October 2025 for renovations and crew training with the U.S. Third Fleet. Live-fire training is scheduled for August, before JS Chokai returns to its home port in Sasebo Naval Base in the southwestern Kyushu Island in September.

Japan is moving toward a “denial and limited strike” model by fast-tracking the implementation of its 2022 strategy, maritime security expert Benjamin Blandin told Defense News. Blandin is a research fellow at the Institute for National Defense and Security Research in Taiwan.

“Japan is operationalizing a long overdue counterstrike capability, shifting from strict homeland defense to semi-regional deterrence by being able to strike ground and naval targets at up to 1000 km,” Blandin said.

Japan’s existing defense force, including its stand-off missile capability, is the “minimum necessary for self-defense,” Koizumi said, adding that these would only be used “in the event of an armed attack from another country … and it does not pose a threat to other countries.”

Analysts have raised worries that the U.S. Tomahawk stockpile may be strained after reports indicated that over 800 missiles were used in four weeks during Operation Epic Fury against Iran, and this might impact missile orders for allies, including Japan.

Blandin said Japan’s Tomahawk orders are unlikely to be affected immediately, but prolonged military campaigns in the Middle East could cause minor to moderate setbacks.

American manufacturer RTX, in a Feb. 4 press release, said it had signed five agreements with the U.S. Department of Defense to boost production and expedite deliveries of Land Attack and Maritime Strike variants of the Tomahawk cruise missiles, with annual production expected to increase to more than 1,000.

“No major impact expected in regards to Iran, as deliveries will not take place all at once but probably over the course of a few years,” Blandin said. “In any case, the U.S. will likely prioritize Japan as a key Indo-Pacific ally.”

On Sunday, the Philippines reported Chinese ships collided with a crewed military supply vessel escorted by two Coast Guard ships en route to BRP Sierra Madre, an actively commissioned ship by the disputed Second Thomas Shoal.

Philippine Army Chief of Staff Gen. Romeo Brawner said changes are geared toward protecting the country’s territories in the South China Sea, particularly Thitu Island. That land mass, called Pag-asa Island by the Philippines, is home to more than 400 Filipinos. It is also one of several disputed islands in the South China Sea.

The third phase of the military’s 15-year modernization plan, dubbed Horizon 3, includes the acquisition of multirole fighter jets, radars, two additional Jose Rizal-class frigates, missile systems, helicopters and the country’s first submarine fleet.

Initial plans also included acquiring additional BrahMos missiles and High Mobility Artillery Rocket Systems for the Army for coastal defense.

The modernization effort began in 2013, but budget limitations have delayed progress. Defense Secretary Gilberto Teodoro told lawmakers last month that 10% of Horizon 1, meant to take place from 2013 to 2018, and about 53% of Horizon 2, scheduled from 2018 to 2022, are complete.

“That is why we have to re-strategize, because the paradigms for Horizon 2 may not be valid anymore,” Teodoro said at the time.

However, in response to clashes between China and the Philippines in recent weeks, Manila is speeding up its acquisition plans, with the legislature earmarking 45 billion pesos (U.S. $793 million) in defense spending for 2024. Senators have relayed support in passing supplemental budgets for intelligence and materiel acquisitions related to South China Sea operations.

Last week, the Defense Department ordered three C-130J-30 Super Hercules tactical airlifters for delivery in 2026, according to a news release from Lockheed Martin. The Philippines is also expecting to receive two BrahMos missile units in December from India; more Acero-class gunboats next year under a deal with Israel; two new landing dock platforms from Indonesia next year; two corvettes from South Korea around the 2025 and 2026 time frame; and six offshore patrol vessels also from South Korea in 2028.

Horizon 3 requires 500 billion pesos spread out over the next six years, but it is unclear how the government intends to finance the program. However, some countries have offered assistance. For example, France pitched its Scorpene diesel-electric submarines as early as 2019, and its proposal includes helping the Philippines Navy develop its base in Zambales.

Others bidding to supply the Philippines with submarines include Spain, which submitted a $1.7 billion offer to supply two S-80-class sub, and South Korea’s Hanwha Ocean, which updated its proposal last month for two Jangbogo-III diesel-electric submarines.

While the Philippine military has yet to release its final plans for Horizon 3, the realignment will include less but “more potent” assets and platforms, according to Brawner. The materiel will align with the country’s forward-defense strategy, where threats are “pushed as further away as possible,” Brawner said, adding that the military’s goal is to immediately deploy fighter jets and other assets after reported encounters with Chinese vessels.

According to the country’s new territorial defense strategy released last week, the Philippines is placing particular importance on islands it claims as its own, including in what the government calls the West Philippine Sea, namely Thitu Island, Loaita Cay, West York Island, Flat Island and Nanshan Island.