Japan is building up its ‘southern shield’ as it faces its most severe and complex security environment since 1945. The country has deployed long-range missiles to Kumamoto Prefecture on its southwest coast, which could potentially target China, which has been ranked as Japan's top national security threat since 2019. The Japan Self-Defense Forces (JSDF), Japan's military, which is formally known as the country’s military, have deployed a range of weapons platforms and electronic warfare and air assets in southern Japan and its southwest outlying islands. The strategy focuses heavily on the Nansei or Ryukyu Islands, which form a natural barrier between the East China Sea and the Taiwan Strait. It also incorporates a shift in Japan's defence policy towards acquiring “counterstrike capability” that would allow the JSDF to respond if attacked. These contradictions define the modern JSDF, which emerged from Japan's post-war police during the US occupation.