What were the strengths of the U.S.'s enemies during World War II?

There were two major strengths that the Axis Powers enjoyed in
WWII. (I am speaking mainly of Germany and Japan here.) These were that A) they were much more
ready to fight and B) they had more experience and better war plans than the Allies originally
did.

When WWII broke out, the Germans and Japanese were ready to
fight where the Allies were not. The Axis had been planning the war and were naturally more
prepared for it than the Allies. The Germans had much better plans for the war (the new tactic of
blitzkrieg) than the Allies had. The Japanese were much more experienced at fighting because of
their recent experience in China.

It is also worth mentioning that
the Axis had better weapons in some significant ways. For example, both the Germans and Japanese
had better airplanes at first than the Allies did.