They're already attacking our business industries and personal lives with 40+ inch 4k resolution gaming monitors for under $400 on the web. Once every American has one they'll be too obsessed with their computers to care about being attacked..
perhaps they should...
Hearken back to the second world war; the U.S. economy was **** before we got involved, but was chugging along like a happy steam engine when the war ended. I wouldn't mind that happening again, even if it meant I got drafted.
On the other hand, the above example is extremely optimistic, and doesn't account for the probability that an all-out war might make the economy worse, let alone the chance we might lose.
One big reason that the American economy did so well is that we still had the capability for mass industrialization, which is because we were barely attacked. If we were ever seriously attacked, the war wouldn't be nearly as beneficial.