Question

How did the united states respond to increasing totalitarian aggression in europe and asia

Answer 1

At the start of World War II, the United States wanted to remain neutral.  American laws passed in the 1930s were meant to ensure that the US did not get entangled in another foreign war the way it had in WWI.  However, President Roosevelt felt that Germany was a major threat to US interests and was gradually moving the US towards greater involvement.  He did this through such things as the "destroyers for bases" deal with England.  In time, he was able to persuade Congress to pass the Lend-Lease Act in which the US started to send supplies to the Allies.  By doing things like this, Roosevelt was able to get the US more involved in the war while remaining officially neutral.

Answer 2

The United States gradually abandoned neutrality as events in Europe and Asia pulled the nations toward war. I hope its help .. :) 
I have history honors ...