Joint Japan-U.S. military drill set to break new ground

What happened: The biannual U.S.-Japan Keen Sword 27 exercises begin Monday, described as a dress rehearsal for defending Japan's southwestern island chain, with many firsts expected. Key numbers: About 45,000 Self-Defense Force personnel and 12,000 U.S. service members take part. Japan deploys Type 25 surface-to-ship missiles outside Kumamoto Prefecture for the first time. The U.S. Why it matters: The drills are the largest ever and mark first-time deployments on both sides, including Japan's longer-range missiles and a U.S. anti-ship system on an island close to Taiwan.

The biannual U.S.-Japan Keen Sword 27 exercises begin Monday, described as a dress rehearsal for defending Japan's southwestern island chain, with many firsts expected.

The drills are the largest ever and mark first-time deployments on both sides, including Japan's longer-range missiles and a U.S. anti-ship system on an island close to Taiwan.