In 1938, when hitler took over austria, thedid nothing, so he attacked czechoslovakia.

britain and france

Explanation:

At the Munich Conference, Hitler demanded that the Sudetenland be joined with Germany. Britain and France feared Germany's military strength, and knew they were not prepared for the war, so they gave in to the demands. This method of keeping the peace by accepting some of the demands of the aggressor is Czechoslovakia was left defenseless as the United States also tried to avoid the conflict.     hope it helps

nuclear fission produces the atomic bomb, a weapon of mass destruction that uses power released by the splitting of atomic nuclei the fighting in iwo jima and okinawa affected the allies' pacific strategy because truman decided to drop the atomic bomb on mainland japan.