In 1942, with Nazi Germany occupying much of the USSR, Sheng saw the Soviet Union's weakness, and turned anti-Soviet, expelling Soviet advisors and executing many Han Communists, including Mao Zemin, Mao Zedong's brother. He hoped to secure the backing of the Kuomintang (KMT, Chinese Nationalist Party) for his continued rule. However, when the fighting in Europe swung in favor of the Soviet Union after the Battle of Stalingrad, Sheng attempted to expel the KMT, and sent a letter to Stalin requesting Soviet aid.