 In 1937, when the Second Sino-Japanese War erupted, Sun resurfaced once again, commanding troops against the Japanese, taking command of the Hebei-Chahar Guerillas in 1938.He was eventually appointed as general of the NRA's 5th Army, but alongside his superior Pang Bingxun defected to the Japanese in 1943.Joining Wang Jingwei's Reorganized National Government of the Republic of China, he was given command of Collaborationist Chinese Army's 6th Group Army District which guarded the southern Beijing–Hankou railway, and was made a member of its National Military Council.