Without a written certification letter, Drax did not have the power to guarantee anything to the Soviet Union and had been ordered by the British government to extend the talks as long as possible and avoid the question of whether Poland would agree to allow Soviet troops to enter the country if the Germans invaded the country. [65] When negotiations failed, a great opportunity to prevent German aggression was probably missed. [66] The previous year, Hitler had annexed Austria and seized the Sudetenland from Czechoslovakia; In March 1939, his tanks rolled throughout the rest of Czechoslovakia. He seemed determined to roll back the international order established by the Treaty of Versailles, the 1919 peace settlement that ended World War I (1914-18). (The treaty, which demanded many concessions and reparations from Germany, was very unpopular with Hitler and his Nazi party.) It also seemed that Hitler planned to get ahead of his Polish neighbor afterwards.