evidence: 1958 - Taiwan Strait Crisis. Communist China shells the Nationalist-controlled islands of Kinmen or Quemoy and the Matsu Islands to probe the extent of the US support for Taiwan. Air and attempted amphibious landings see about 1,000 troops killed. [...] 1979 - Washington switches diplomatic recognition to Beijing from Taipei. US Congress passes the Taiwan Relations Act promising to help the island defend itself. [...] 2022 - Relations between Taiwan and China deteriorate sharply following a visit to the island by US House Speaker, Nancy Pelosi. China carried out military exercises, including the firing of ballistic missiles, focussing on six zones around Taiwan, three of which overlap the island's territorial waters.