A powerful Pacific typhoon is doing more than wrecking travel plans.
Typhoon Champi, one of the strongest storms to hit the western Pacific this year, has forced more than 200 flight cancellations across Taiwan and Japan while disrupting one of the biggest U.S.-Japan military exercises in the region.
The timing is especially significant. The storm is interfering with Keen Sword 27, a massive multinational military exercise involving roughly 56,000 American and Japanese personnel and taking place across strategically important parts of Japan.
According to Reuters’ October 22 report, Champi had previously reached super-typhoon strength before weakening somewhat as it approached Taiwan.
But “weakened” is relative.
The storm was still producing gusts of up to roughly 227 kilometers per hour, or 141 mph, with a circulation spanning hundreds of kilometers.
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Flights Canceled as Taiwan Braces for the Storm
Taiwanese authorities canceled 125 domestic flights as the storm approached, while residents in vulnerable coastal and mountainous areas were warned to stay away from dangerous locations.
Officials were also preparing for potentially extreme rainfall, particularly in northern mountainous regions.
Taiwanese President Lai Ching-te urged residents to remain alert as forecasters tracked Champi’s path.
Japan was already feeling the effects as well.
More than 100 domestic flights in Japan were canceled, affecting over 11,000 passengers, according to Reuters. That pushes the combined number of canceled flights in Taiwan and Japan above 200.
The storm is expected to affect Japan’s southwestern islands, including parts of Okinawa Prefecture.
And that is where the story becomes more than a weather disruption.
Typhoon Collides With Massive U.S.-Japan Military Exercise
Keen Sword 27 began on October 19 and is scheduled to continue through October 29.
The exercise includes roughly 45,000 Japanese Self-Defense Forces personnel and 11,000 U.S. service members, according to official figures.
Japan’s Joint Staff has described Keen Sword as a major bilateral joint exercise aimed at improving coordination between Japanese and American forces. Japan’s Joint Staff lists Keen Sword 27 among its official 2026 exercises and announcements.
Australia is also participating with nearly 300 personnel. The Australian Department of Defence said the broader exercise includes approximately 40 vessels and 260 aircraft, with Canada, France, Germany, New Zealand, the Netherlands and the Philippines also participating alongside Australia.
The scale matters.
This is not a small training event at a single base. Keen Sword stretches across Japan and surrounding waters and is designed to test how allied forces coordinate during complex regional emergencies.
Now, commanders are having to adjust that training around a real-world threat from Mother Nature.
Reuters reported that training activities were being reviewed and adjusted on a daily basis because of the typhoon.
Some planned training has already been canceled or modified, while weather conditions could force additional changes depending on Champi’s path.
The Location Makes the Disruption More Important
Much of Keen Sword’s activity is focused on Japan’s southwestern islands — a chain that extends toward Taiwan and sits near some of the most strategically sensitive waters in Asia.
That gives the exercise obvious significance at a time of growing tensions involving China, Taiwan, Japan and the United States.
The exercise was planned long before Typhoon Champi appeared, and U.S. and Japanese officials have characterized Keen Sword as defensive training rather than an operation aimed at any single country.
Still, the geography is impossible to ignore.
Japan and the United States have increasingly focused military planning on the defense of remote islands and the ability to keep forces supplied and coordinated during a crisis.
Keen Sword is intended to test exactly those capabilities.
Champi is now adding an unscheduled test: whether the exercise can keep moving when severe weather shuts down aircraft, disrupts transportation and forces commanders to abandon parts of the original plan.
Champi’s Next Move Could Decide How Much Training Survives
The biggest unanswered question is how close the typhoon will come to Japan’s southwestern islands and how long dangerous conditions will remain.
Exercise commanders have so far emphasized that the overall Keen Sword mission is continuing, even as individual activities are modified.
But with the storm still moving through a strategically important region, further cancellations remain possible.
For travelers, Champi has already created chaos.
For the U.S. and Japanese militaries, it has turned a carefully planned exercise into something slightly more realistic: an operation where the schedule suddenly stops mattering and commanders have to adapt.
