Am going to guess of Cold War and Desert Storm?
The Cold War was an absolute necessity. When I was on the F-111E (RAF Upper Heyford), I managed to snag a controlled tour to East Berlin. Yes, back then active duty personnels can play tourists in communist countries under appropriate conditions, anyway, after three days in East Berlin, I returned to the West with renewed conviction that resisting communism was the morally righteous thing to do.
As for Desert Storm, Iraq under Saddam Hussein must be contained and after the invasion of Kuwait, he sealed his own fate with his own pen. But after DS, it was at best a C- on how the US occupied and ran the country. Some things we did right, some not. To this day, speaking for myself, I do not believe DS was the wrong thing to do, and that it was necessary.