Throughout the 1930's, appeasement was failing to stop the axis powers from wrecking havoc in the east. Appeasement is the act of giving in to demands in return for peace. Germany, Italy, and Japan formed the axis powers. The combination of German aggression, Japanese attacks, and poor Italian leadership was getting to be too much for the United States to stand. At this point, the U.S. was beginning to turn from isolationism to action.
Beginning in 1930, Adolf Hitler sent his re-armed military into the Rhineland. This part of Germany was protected by the Treaty of Versailles. Hitler did not pay the consequences for his actions, and Germany went on to renounce the Treaty of Versailles. Also, Germany signed the Axis Pact with Italy in 1936. Later in the same year, Germany agreed to the Anti-Comintern Pact with Japan, which was led by military General Tojo. The agreement was aimed at Russia, and formed the Berlin-Rome-Tokyo axis. In 1937, Germany annexed Austria. Then in 1938, Hitler demanded the annexation of Sudetenland, in western Czechoslovakia. This area was inhabited by over two million ethnic Germans. This sparked the Munich Agreement in September of 1939. Hitler is quoted "This is the last territorial claim I have to make." Prime Minister Neville Chamberlain countered by declaring "Peace in our time." In the end, Sudetenland got annexed. Also in 1939, Germany signs a non-agression pact with Russia. Should war break out, they would not attack eachother.
In response to the fall of the Soviet Union, the Atlantic Charter was organized. This charter opposed imperialistic annexations, while promising that there would be no territorial changes contrary to the wishes of inhabitants. It also affirmed the right of people to choose their own form of government. It aimed at reestablishing the governments abolished by the dictators. The charter also demanded a "permanent system of general security.