From June 18, 2020 through June 20, units from Japan's Self Defense Force (JSDF) and the United States Navy (USN) tracked the movements of a Chinese submarine in Japanese waters. Subsequently, US and Japanese assets sought to force the sub-surface contact into international waters. The incident marks the first time a submarine of the People's Liberation Army Navy (PLAN) has been discovered in Japan's contiguous zone since 2018.
The cat and mouse game reportedly began on June 18, when the JS Kaga (DDH-184), a Japanese helicopter carrier, stumbled across an unknown sub-surface contact 24 miles off the coast of Amami-Oshima island. Soon after the initial discovery, a Kawasaki P-1 maritime patrol aircraft also detected the submarine, but this time 25 miles from the island. The JSDF and unspecified USN assets continued to monitor the sub as it transited the narrow strip of water between Amami Oshima and Tokara island without surfacing. Finally, after 45 hours of surveillance, evasion, and detection by both sides, the Chinese submarine left Japanese waters and returned to international lanes of traffic.
For well over a month, the United States has accused the People's Republic of China of using the COVID-19 crisis to further its claims in the South China Sea. On April 23, Secretary of State Mike Pompeo wrote in a joint statement with other members of the Association of Southeast Asian Nations (ASEAN), "The CCP (Chinese Communist Party) is exerting military pressure and coercing its neighbors in the SCS, even going so far as to sink a Vietnamese fishing vessel. The US strongly opposes China's bullying and we hope other nations will hold them to account too." Secretary Pompeo further went on to criticize the PRC's implementation of new administrative districts around both the Islands and Spratly Islands, a clearly antagonistic move that will not be taken lightly in most ASEAN members capital cities.