You need to remember the human factor. Back then we were a unified nation with people of values. We're becoming a conglomeration of diverse selfish interests now. I recognize we were isolationists then, but we lifted our nation out of the ashes of Pearl Harbor and became a fierce animal.
After 911 we gave taxpayer money to family victims of the World Trade Center and thought we had done something significant.
We might be stronger on paper than before WWII, but we won't have the allies we had after 12/07/1941. Our enemies know this.
However, your point is well taken.