On Japan's Yonaguni island, fears of being on the front line of a Taiwan conflict

The seashore on southwest Japan's Yonaguni island. (Anthony Kuhn/NPR)

YONAGUNI ISLAND, Japan — For years it was known as the "Two Gun" island – one gun for each of the two policemen stationed here.

Yonaguni, Japan's most westerly island, can feel like a peaceful paradise — it is covered in tropical forests and hammerhead sharks glide through its azure waters.