Yeah the US really had it's arms tied in Vietnam
6,727,084 tons of bombs dropped on Indo China by the US during the Vietnam War.
2,700,000 tons dropped by Allies in European theather
656,400 tons dropped by Allies in Pacific war
So around double the tons of bombs dropped on a relatively small region compared to the entire allied bombing combined in WWII in Europe and the Pacific.
So hard to win a war when you are so restricted!