I agree that external supply along the Ho Chi Minh trail was a shaping factor for the Viet Nam conflict. In fact, the thing that General Giap feared the most was American troops physically cutting off the trail rather than bombing it. He never could understand why they didn't.
The most relevant fact about political support in the US in Viet Nam is: that the US army never even thought about the consequences of using a strategy that caused so much death and destruction in Viet Nam on political support in the US. General Giap understood Sun Tzu(Even Mao borrowed heavily from Sun Tzu) which gave him a strategic advantage: He understood that the will of the Viet Namese and American people were the two most significant factors shaping the conflict.
If you look at the Viet Nam conflict through the lenses of Clausewitz:
1. The people are a center of gravity, that provide the hate that fuels the will to win against all odds and explains why propaganda and the demonetization of the other are important aspects of warfare.
2. The army employs creativity to develop tactics and strategy that outwit and defeat the enemy.
3. The government is the rational goal setter of the war that decides when to start and end a war.
It's obvious the US failed on all three of Clausewitz's levels in Viet Nam.
The best research paper that I ever read at the combined arms research library was a method to evaluate strategy or tactics by ends, ways and means.
The author described America's strategy in Viet Nam as: The perfect strategy(ways) to expend an infinite amount of resources(means) to achieve nothing(ends).
Sir, that idea sums up my opinion on Israel's strategy vs the Palestinians; and the occupation of Iraq and Afghanistan. lol
I'll explain now why I believe that the pattern of national liberation struggle is appropriate to the conflict between Israel and the Palestinians.
General Giap understood that both the American and Viet Namese people were both centers of gravity and that they were both won or lost on the moral level.
He understood that anything he or his army did that the Vietnamese and American thought was moral helped him to win.
He also realized that anything that the American army did that the Vietnamese and American people thought was immoral helped him to win.
Neither the Israel or the Palestinians have grasped that and neither side has tried to win the others center of gravity.
The relevant facts about Israel vs the Palestinians are: Israel won over 50 years ago and kicked them out of most of their lands.
There has been a hot/cold conflict for over 50 years.
Palestinian asymmetrical warfare terrorist tactics haven't forced Israel's people to give them a good enough peace deal.
Israel's efforts to force the Palestinians into accepting a bad peace deal hasn't worked.
Neither side has tried winning the other side's center of gravity ie the people through winning on the moral level.
Israel's unwillingness over the last 30 years to give the Palestinians an acceptable peace deal has caused and still causes all sorts of problems for American interests in the middle east.
Israel is an island of 7 million jews living in a sea of a couple hundred million muslims.
Sir, Thinking as the rational goal setting government in Clausewitz's people/army/government trinity the most logical conclusion I can come to:
30 years ago, America should have held Israel's feet to fire and forced them to give the Palestinians a good enough peace deal. Offer Israel a guarantee of national security and tell them to stop behaving like a bad ally.
I thought you might like to read this: Moshe Dayan's impression of america in Viet Nam
http://www.shalomctr.org/node/641