The Second Sino-Japanese War began on 7 July 1937 with the Marco Polo Bridge Incident in the Republic of China and is often regarded as the start of World War II as full-scale warfare erupted with the Battle of Shanghai, and ending when the Empire of Japan surrendered to the Allies in August 1945. The Chinese Air Force faced the Imperial Japanese Army and Navy Air Forces and engaged them in many aerial interceptions, including the interception of massed terror-bombing strikes on civilian targets, attacking on each other's ground forces and military assets in all manners of air-interdiction and close-air support; these battles in the Chinese skies were the largest air battles fought since the Great War, and featured the first-ever extensive and prolonged deployment of aircraft carrier fleet