Unlike the 1930s, in 2009 the US lacks the energy and material resources to maintain a permanent global war footing. We have just enough "stuff" for one more really big war. Energy resources in the Middle East will be seized by military force as the costs of the Iraq invasion must be recouped. Chinese or Russian objection to our activities in either sphere will result in a nuclear exchange. I believe we'd much rather have this fight with China than with Russia.
The Japanese and Germans in the 1930s were reduced to similar tactics because they needed energy and material resources to maintain their military machinery.