Re: B52s/B2s...
1) Airpower can suppress opposition but
The opposition comes from your own voters.
Stealth aircraft look cool and you don't get many dead pilots if you stay high enough.
2) ground forces are needed to drive them out and
Why would you want to drvie them out, good enemies are hard to find these days.
3) political will is needed to keep them out.
Commies are funny now and since we have fracking we don't even want to keep them out of countries that have oil
4) You can't indefinitely occupy a country whose inhabitants don't _want_ to be occupied and (Soviets in Afghanistan?)
That's why the Brits always split the country and let them fight each other - works for centuries.
5) you don't win hearts and minds by dropping bombs on some bystander's family
Only hearts and minds of congress matter. As long as you build the bomber in their constituency they will support you.
6) (on the other hand, doing so is one of the best recruiting tools for terrorists that exists) case in point: ISIS
ISIS mostly kill other people that we would be killing. We will get round to re-doing the terrorist league tables next year.