WW2 was not a war of choice for the US. It was attacked.
I agree that infrastructure investment makes a sensible next step in the recovery process. But the US has a Republican party. So sensible is impossible.
Personally, I think Ben Bernanke has done a great job with the Fed during the crisis, acting as the lender of last resort, injecting liquidity etc. And astonishingly, in spite of the increase in the principal value of the debt, the interest burden on the US government has diminished during this crisis.