One of the reasons air power did no prevail in Nam was because we keep agreeing to cease fires and halting the bombing which gave the VC time to rest, regroup, and rearm.When you have your enemy on their heels it's never a good idea to call a time and let them recover.
Don't recall that we ever gave the VC a break from bombing. Bombing breaks, when they occurred, were given to N.Vietnam. That being said, it wasn't bombing halts that led to our failure in VN. That was because it was a civil war and they weren't going anywhere. The only possible way we could have won was by invading the north, but the proximity to China and the memory of what happened in Korea prevented that. Our experience in VN is also why I was opposed to the invasion of Iraq. We were already involved in a civil war in Afghanistan, so when Bush took his eye off the ball I knew that was a likely loser too and here we are 11 years later staring the same situation in the face.