 The Twenty-Second Army was a part of the Japanese Southern China Area Army, whose officers, remembering the Mukden incident of 1931, were trying to force their superiors to adopt a more aggressive policy.Following the Đồng Đăng incident, Decoux cut off negotiations.On 18 September, Nishihara sent him an ultimatum, warning that Japanese troops would enter Indochina regardless of any French agreement at 22