the remilitarization of the Rhineland by the ratification of the treaty in the French parliament, claiming that he felt threatened by the pact. However, after 1936, the French lost interest, and all parties in Europe realized the treaty was effectively a dead letter. The appeasement policies of the prime ministers of Britain and France, Neville Chamberlain and Édouard Daladier were widely held because they seemed to promise what Chamberlain called "peace for our time." However, by early 1939 it was clear that it further encouraged Nazi aggression. The Soviet Union was not invited to the critical Munich conference in late September 1938, where Britain, France, and Italy appeased Hitler by giving in to his demands to take over the Sudetenland, a largely German-speaking area of Western Czechoslovakia. Distrust was high in all directions. Leaders in London and Paris felt that Stalin wanted to see a major war between the capitalist nations Germany on the one hand, and Britain and France on the other, in order to advance the prospects of a working-class revolution in Europe. Meanwhile, Stalin felt the Western Powers were plotting to embroil Germany and Russia in war in order to preserve bourgeois capitalism. After Hitler took over all of Czechoslovakia in 1939, proving appeasement was a disaster, Britain and France tried to involve the Soviet Union and a real military alliance. Their attempts were futile because Poland refused to allow any Soviet troops on its soil. Diplomats purged In 1937–1938, Stalin took total personal control of the party, by purging and executing tens of thousands of high-level and mid-level party officials, especially the Old Bolsheviks who had joined before 1917. The entire diplomatic service was downsized; many consular offices abroad were closed, and restrictions were placed on the activities and movements of foreign diplomats in the USSR. About a third of all foreign ministry officials were shot or imprisoned, including 62 of the 100 most senior officials. Key ambassadorial posts abroad, such as those in Tokyo, Warsaw, Washington, Bucharest, and Budapest, were vacant. Non-Aggression Pact with Germany (1939–1941) In 1938–1939, the Soviet Union attempted to form strong military alliances with Germany's enemies, including Poland, France, and Great Britain, but they all refused. In an effort to delay a Nazi invasion and build up the Soviet military, Stalin made a non-aggression pact with Hitler and received control of a large swath of Eastern Europe, including the Baltic countries.