ISolationism
Isolationism was strongest in the United States, where oceans separated it on both sides from the war fronts. Having seen their Wilsonian idealism for forgiveness for the Central Powers in World War I rejected, some Americans hoped to sit out this "Old World" war. The German-American Bund even marched down the avenues of New York demanding isolationism. The isolationists, led by the America First Committee, were a large, vocal, and powerful challenge to President Roosevelt's efforts to enter the war. Charles Lindbergh was perhaps the most famous isolationist. Isolationism was strongest in the Midwest with its strong German-American population.
Appeasement
Appeasement means giving in to someone provided their demands are seen as reasonable. During the 1930s, many politicians in both Britain and France came to see that the terms of the Treaty of Versailles had placed restrictions on Germany that were unfair. Hitler's actions were seen as understandable and justifiable. When Germany began re-arming in 1934, many politicians felt that Germany had a right to re-arm in order to protect herself. It was also argued that a stronger Germany would prevent the spread of Communism to the west.
In 1936, Hitler argued that because France had signed a new treaty with Russia, Germany was under threat from both countries and it was essential to German security that troops were stationed in the Rhineland. France was not strong enough to fight Germany without British help and Britain was not prepared to go to war at this point. Furthermore, many believed that since the Rhineland was a part of Germany it was reasonable that German troops should be stationed there.
In 1936, Hitler argued that because France had signed a new treaty with Russia, Germany was under threat from both countries and it was essential to German security that troops were stationed in the Rhineland. France was not strong enough to fight Germany without British help and Britain was not prepared to go to war at this point. Furthermore, many believed that since the Rhineland was a part of Germany it was reasonable that German troops should be stationed there.