I guess you're not talking about some well-executed surgical strike to take out the leadership? Because Ho Chi Minh, Giap and other NV leaders were moving aroun

I guess you're not talking about some well-executed surgical strike to take out the leadership? Because Ho Chi Minh, Giap and other NV leaders were moving around the country with impunity throughout the war, and the US never came close to working out where they were or taking them out, so poor was their intelligence. So yeah, the US could have won by going nuclear, as Nixon briefly considered at Khe Sanh. But that wouldn't have turned the war, he would have had to escalate to nuking Hanoi. And destroying an entire population to effect regime change is not really "winning" in any sense of the word. There was nothing simple about winning in Vietnam, and the US was never in any position to crush the North.