塘沽协定
A secret clause of the Tanggu Truce excluded any of the Anti-Japanese Volunteer Armies from the Peace Preservation Corps. This effectively meant that the Japanese Army was able to dominate the Peace Preservation Corp with demobilized troops from the collaborationist proxy Chinese armies which had participated in the Battle of Rehe and the subsequent attack on the Great Wall and the intrusion into Hebei. Some 1,000 men were recruited into the Corps from the former troops of warlord Shih Yusan and a further 2,000 men from the forces of Li Chi-chun.