The Keen Sword 27 joint military exercises primarily focus on defending Japan's southwestern islands and northern coastal waters against security challenges from China, North Korea, and Russia.

From the articleJapan and U.S. kick off one of their largest joint military drills defending Japan's southwestern islands as tensions with China rise | FortuneAlso in Japan and the US kick off joint drills around islands as regional tensions rise, Japan and the US kick off joint drills around islands as regional tensions rise