If we had remained in Iraq, for example, ISIS wouldn't have gotten nearly as far as it did.
As far as bombing Iran...you can't indiscrimately bomb without intel. We would have had a lot more intel of the area with boots on the ground.
You were talking about developing nuclear weapons.
Our troops on the ground next door can do nothing about that. We’d have to take out their facilities with airstrikes. Israel has no problem getting intel w/o putting large ground troops in place.
If we remain in Iraq a lot of things may or may not happen. How long do we stay there? 50 years? 100 years?
No matter when we go the place will devolve into internecine warfare .... as it has for millennia.
Again, what is there to gain for us unless we are getting paid vast sums by staying? In which case the soldiers are getting screwed because they are not sharing in the booty.