Japan and the United States opened Keen Sword 27 on Monday, Oct. 19, 2026, launching one of their largest joint military exercises with about 45,000 Japanese and roughly 12,000 U.S. personnel. The drills run through Oct. 29 and center on defending Japan’s southwestern islands, the chain that stretches from Kyushu past Okinawa to within about 110 kilometers of Taiwan, the Associated Press reported.
Keen Sword 27 by the numbers
- Dates: Oct. 19 to Oct. 29, 2026.
- Japanese forces: about 45,000 personnel, 6,100 vehicles, 40 vessels and 260 aircraft, according to Japan’s Joint Staff, as reported by USNI News.
- U.S. forces: about 12,000 service members, per AP. Keen Sword spokesman Maj. Ephesian Poinsette told Stars and Stripes the U.S. expected to field approximately 11,000 troops plus the USS Theodore Roosevelt carrier strike group.
- Partner nations: Australia, Canada, France, Germany, the Netherlands, New Zealand and the Philippines. Japan’s Joint Staff said France, Germany, the Netherlands, New Zealand and the Philippines are taking part for the first time. South Korea and the United Kingdom are sending observers, according to Poinsette.
- Main areas: western and southern Japan, the Okinawa island chain, the Sea of Japan and the East China Sea, with drills on remote islands including Yonaguni, Ishigaki, Tanegashima and Oki-Daito.
Keen Sword is a biennial field-training exercise that has been held since 1985 and alternates with a command-post exercise. This edition follows our preview of the Keen Sword 27 deployments to Yonaguni and the Sakishima Islands, published before the drills began.
Keen Sword troop participation, 2022 to 2026
Approximate personnel in the last three field-training editions. 2026 U.S. figure as reported by AP; a Keen Sword spokesman told Stars and Stripes about 11,000.
How the exercise has grown
Japanese participation has risen sharply over the last three field-training editions. In 2022, Keen Sword 23 involved 26,000 Japanese and 10,000 U.S. personnel, with Japan sending 20 ships and 250 aircraft, USNI News reported at the time. In 2024, Keen Sword 25 grew to about 33,000 Japanese personnel, 30 ships and 250 aircraft, alongside about 12,000 U.S. personnel, 10 ships and 120 aircraft, according to the Japan Joint Staff’s exercise page.
That means Japan’s contingent this year is about 36% larger than in 2024 and roughly 73% larger than in 2022. The number of partner nations actively participating has also roughly doubled from 2024, when Australia and Canada were the only participants beyond the two allies, Stars and Stripes reported.
Japanese ships and aircraft committed to Keen Sword
Vessels and aircraft announced by Japan's Joint Staff for its own Self-Defense Forces in each edition.
Carrier strike group and live fire
The aircraft carrier USS Theodore Roosevelt, flagship of Carrier Strike Group 9, left Yokosuka and steamed out of Tokyo Bay on Monday to join the exercise. The carrier had arrived at Yokosuka on Oct. 16 with the guided-missile cruiser USS Chosin and the guided-missile destroyer USS Decatur for maintenance and resupply, the U.S. Navy said. Stars and Stripes reported that the strike group also includes the destroyers USS Paul Hamilton and USS Carl M. Levin.
The training program covers air and missile defense, maritime and amphibious operations, minesweeping, intelligence gathering, resupply, casualty evacuation and facilities repair. On the first day, Japanese and U.S. troops were scheduled to conduct live-fire drills at a range on Oki-Daito, an uninhabited island about 500 kilometers southeast of Okinawa, according to AP.
Missiles on Yonaguni and Ishigaki
Yonaguni, Japan’s westernmost island, is one of the exercise’s key locations. Japan’s Ground Self-Defense Force brought its first long-range Type-25 land-to-ship missile to the island for the drill, though no test-firing is planned, AP reported. The missile has a range of about 1,000 kilometers. It is the first time the Type-25 has been deployed away from its base for training since it entered service in March, Kyodo News reported.
The U.S. Marine Corps has sent two of its newest systems to Yonaguni for the first time: NMESIS, a ground-based anti-ship missile launcher, and MADIS, a short-range air defense system. The Army’s HIMARS mobile rocket launcher has been deployed on nearby Ishigaki, where the opening ceremony was held.
Regional context
The exercise comes as Japan’s relations with China remain strained. AP noted that ties worsened after Prime Minister Sanae Takaichi said a year ago that Chinese military action on Taiwan could justify Japanese involvement. Japan has also voiced concern about Chinese military activity around its remote Pacific islands, and has strengthened its southwestern defenses with longer-range missiles and interceptors. For more on tensions in the region, see our report on the Philippines summoning China’s ambassador and the Geopolitics hub.
The drills also come weeks after a U.S. Marine was arrested in connection with the murder and robbery of a Japanese woman on Okinawa, a case AP said has renewed anti-base sentiment on the island.
Reactions
Japan: Gen. Hiroaki Uchikura, chief of staff of Japan’s Joint Staff, denied that the exercise targets a specific country, AP reported. At the Ishigaki opening ceremony, Adm. Tateki Tawara said, “In order to do so, it is essential to be fully prepared and cooperate with our allies and partners to prevent the crisis,” referring to protecting the peaceful lives of residents, according to the Joint Staff.
United States: “This is about training how our forces work together,” Poinsette told Stars and Stripes, adding that the drill is “not directed at a particular country or a response to a single regional event.” He called it a “routine, defensive training exercise.”
China: At its Oct. 19 briefing, China’s Foreign Ministry did not address Keen Sword directly, but spokesperson Mao Ning said China “firmly opposes and strongly condemns” recent Yasukuni Shrine offerings by Japanese leaders, according to the ministry transcript. The state-run Global Times quoted Lü Chao of the Liaoning Academy of Social Sciences describing the Type-25 deployment as “a clear provocation.” A day before the drills, China’s navy publicized four Type 071 amphibious ships firing live rounds together, Taiwan Defence reported.
Local residents: Groups in Oita and Fukuoka prefectures submitted petitions asking for the exercise to be canceled, and residents of Miyakojima raised concerns at a public meeting about Osprey flights, possible accidents and incidents involving U.S. personnel, according to Japanese media reports cited by the Global Times.
Sources
- AP: Japan, US kick off major joint drills focusing on southern islands
- Stars and Stripes: US carrier strike group en route to multinational exercise around Japan
- USNI News: U.S., Japanese forces to rehearse defense of Japan’s Southwest Islands
- U.S. Navy: USS Theodore Roosevelt arrives in Yokosuka
- Japan Joint Staff: Keen Sword exercise page (Japanese)
- USNI News: U.S. and Japan prepare for joint exercise (2022)
- China Ministry of Foreign Affairs: Oct. 19, 2026 press conference
- Global Times: Keen Sword 27 drills to begin amid protests in Japan
- Taiwan Defence: China airs live-fire salvo by four Type 071 landing ships
Read next in World News
Like this story? Get the newsletter
New Boston Report stories delivered to your inbox, with links to the full articles.
Free. Confirm by email, unsubscribe anytime. Signups are handled by Jetpack/WordPress.com. Privacy Policy
Most read this week
- Keen Sword 27: U.S. and Japan Open Largest-Ever Island Defense Drills
- Fire Hits St. Petersburg Oil Terminal in Massive Drone Attack on Russia
- U.S. Economic Policy Explained: Tariffs, $2 Trillion Deficit and a Cooling Job Market
- 2026 Midterm Elections: Control of Congress, Key Dates and What to Watch
- Fed Interest Rate Outlook: Hot September CPI Lifts Odds of an October Hike
Latest
- France Orders Overnight Curfews in Parts of Paris and Nice After Weekend Riots
- Repeating DNA Stretch in FAM193B Gene Linked to Higher Alzheimer’s Risk
- ‘Street Fighter’ Wins the Weekend Box Office, but A24’s Holmes Documentary Steals the Show
- Disney’s Character.AI Deal: $20 Million License, Staff Hires and a Bankruptcy Fight
- Hacker Used AI Agents to Breach 100+ Company Websites, Report Says