Besides the occasional sabotages of the supply rout, I agree for the most part with you on that point; to further explain on the sabotages, the Chinese were aggravated that Hanoi refused to toe their line rather than Moscow's and so would simply take supplies as they were transited through China to Northern Vietnam. It was never enough to actually effect the war effort, but it was enough that it was noticeable, and thus strained relations further while making a point.
Everyone has been making excellent observations here. I
dont have a lot of time today, but Ariosto has a clear idea here. It would have been difficult, but if PRC could have been encouraged to go further, especially after Ho Chi Minh's death (he balanced the two forces to keep both PRC and Soviets guessing) then a powerful force would have been focused to send North Vietnam to the table.
All wars are able to be won, hypothetically, but some are nearly impossible, like the war U.K. and Zanzibar, circa 1870, over in 30 minutes with a bombardment.
Wars are really easy to end, too. Just lose.
Losing may well have been more truamatic, but it is not certain if that would have been so. It goes against the grain and would have had nearly certain serious overtones to the geopolitical balance, yet so did 1975.
About less tramatic Vietnam scenarios, anything that lessens the pain, like military competence in a guerilla war setting would help. Looking like fools was part of the pain, and well oiled guerrilla wars have been making idiots of generals for thousands of years.
The point of the futility to prop up the South's feeble regime rings especially true as we did it. You know of the Angolan African adventure? It is apt. There existed three 1975 factions. One the Soviets/Chinese supported. The other the US. The third, UNITA, no one did. The Communist one won and acted like overlords.
This and the fact that they were aided by huge numbers of Cuban troops (outsiders/interloping invaders) alienated the Angolans so much that UNITA grew til owning 80 percent of the country at some times of the 25 year conflict I recall, in part due to tacit and not so tacit CIA/South African help years afterward, but initially all on their own.
Stranger still was that an American oil company (Marathon?) drilling especially in the Cabinda enclave, guarded by large numbers of Cuban troops against forces who are assisted by the CIA. And the oil company lobbying in the US Congress, but I digress.
The point is for Vietnam, the locals had an expression why the US was there. "Either a group of fools or wanting a colony over of Vietnam." And it quickly was sure Americans were no fools. This assessment greatly push and tilt the large majority of the population to be neutral if not hostile to the US and the South Vietnam government.
Compare this to when Singapore wanted its military to make the island more indigestable to Indonesian, Malay, or other trouble makers. They asked the Israelis to come in and modernize their forces. These foreign troops suggested and did so by only 7 members, because if they were listened too, any more are counter productive it was felt by the Israelis.
Yes. They were listened to, and no more were needed.
The modernization was considered effective by the potential opponents. Although the situation was in no way similar to that of Vietnam, the point is clear on how much is possible to achieve.