Adolf Hitler's foreign policy successes during the 1930s were the product of both his country's growing military might and the inept foreign policy practices of France and England. The post-Great War (1914-1918, later to be known as World War I) restrictions placed on Germany by the victorious powers during the peace negotiations at Versailles, France, were both unreasonable and, with respect to restrictions on Germany's ability to rearm, largely circumvented by the government in Berlin anyway. As Hitler and the National Socialist Party grew in strength, Germany's foreign policy became increasingly belligerent and openly confrontational. The Great Depression had weakened the entire continent, but Hitler's grandiose schemes to rebuild Germany and restore its greatness were bearing fruit. As it became more militarily powerful, it became more assertive in its foreign policy.
While Germany grew in strength, the governments of France and Britain were increasingly at a loss as to how to deal with this resurgent Germany. The penultimate event that both solidified Germany's reemergence on the world stage and set the tone for the war that was coming was the Munich agreement of September 1938, in which the western powers acceded to German demands with respect to the German-speaking population of the Czechoslovakian region of Sudetenland. Once Britain, in particular, had acquiesced to German occupation of the territory of another nation, the gate was open for additional Germany demands that culminated in its 1939 invasion of Poland and the "official" start of World War II.
Hitler's bombast and assertiveness in foreign policy was accompanied by a massive buildup of Germany's military and, as importantly, the development of doctrines for the use of the military, most notably the "Blitzkrieg" strategy for lightening-fast armored thrusts into enemy territory while the German Air Force, the Luftwaffe, mercilessly bombed foreign cities and troop encampments. Blitzkrieg tactics caught the west off guard, as it would the Soviet Union when Germany invaded that empire in June 1941, breaking the agreement that had existed between those two countries, part of which was the division of Poland between them. As formidable as Germany's military had become, however, there is no question that diplomatic and military ineptitude on the part of France, Britain and the Soviet Union immeasurably facilitated German triumphs. The age of appeasement embodied in the Munich Agreement was interpreted by Hitler as an invitation to further aggression.