The island chain, also known as the Ryukyus, stretches from Kyushu, the southernmost of Japan’s four main islands, to within 70 miles of Taiwan. Ishigaki is approximately 150 miles east of Taiwan.

The Ishigaki base is part of a belated effort by the GSDF to create a bulwark across an island chain that stretches more than 1,000 kilometers from Japan’s mainland. During the Cold War ...