Although the Empire of Japan was focusing on ending the Chinese war of resistance at the Battle of Chonqing and Chengdu, Kunming was not out of the reach of Japanese air raids, and faced attacks by IJAAF and IJNAF bombers; military assets and infrastructure were under regular attack, while the RoCAF 18th Fighter Squadron and units of the Air Force Academy at Wujiaba were tasked with aerial defense of Kunming. The city of Kunming was prepared as an alternate National Redoubt in case the temporary capital in Chongqing fell, with an elaborate system of caves to serve as offices, barracks and factories, but never utilised. Kunming was to have served again in this role during the ensuing Chinese Civil War, but the Nationalist garrison there switched sides and joined the Communists. Instead Taiwan would become the last redoubt and home of the Republic of China government; a role it fulfills to this day.