In August 1939, shortly before the start of World War II, France and the PCF were shocked by news of the Nazi–Soviet Pact. The PCF leader Maurice Thorez took up the defense of Soviet policies, and consequently the PCF was banned by the Édouard Daladier cabinet; meanwhile, other communists voluntarily broke with Stalinism and sided with the Allies. Sadoul took a conciliatory position. In a letter to diplomat Anatole de Monzie (intended for Daladier's notice), he blamed the Pact on France's "excessive distrust" of the Soviets. He suggested that the Allies could win back the support of Moscow by showing their readiness "to fight a total war" against Nazism. Historian Stéphane Courtois argues that, with Sadoul's help, Stalin sought to downplay his Nazi alliance as a "reversible strategy", and therefore to alleviate the fears of Herriot and Daladier.