Japan views rapidly growing Chinese military activities in and around Japanese territory as a threat and has fortified its southwestern region with longer-range missiles and interceptors.

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