evidence: Tensions have flashed numerous times over the Senkaku Islands, which China calls Diaoyu Islands, including face-offs between Japanese and Chinese warplanes and ships. [...] However, Japan says it saw no trace of Chinese control of the islands in an 1885 survey, so it formally recognized them as Japanese sovereign territory in 1895. [...] Since then, the US has stated ownership of the Senkaku/Diaoyu Islands is a matter between China and Japan, but, under treaty obligations, the US says it would defend the islands because they are administered by Japan.