Another way to look at it, as another battle in the cold war. Problem in wars like this is on how it differs from WWII, WWII was a war to end. After WWII, Korea, Viet-Nam, El Salvador, and all the other places in the world where political battles.
Look at Afghanistan today, Let say we pull out, and a number of years later the T-ban comes back and takes over again. Would you consider Afghanistan a loss?
I hear people argue that the measure of victory was not in hold land. So-called victories for the NLF was in that it over ran some unit or position or place. They would consider that a NLF victory. Yet they say we lost in Viet-Nam, because we did not hold the contested ground.
As I posted the US made a deal with the communists, to let North and South fight it out with out help from outsiders. The US upheld it's agreement the Communists did not. We did not get kicked out of Viet-Nam, we were not in retreat, we were not even there when the South fell (except for some small units). The NFL can not claim a military victory. The can claim a political victory.
There are a lot of reasons why it is a political victory and why for the NLF. Some are wrong, the biggest aspect was mostly internal US politics.
As I posted in the other thread:
One aspect of the Viet-Nam war that became very clear, The effectiveness of propaganda and that the West would not be united, that political infighting in the west would aid in the promoting anti-west propaganda themes. Just like today, propaganda is the most effective weapons against any Western country. The anti-War force, political opponents of those support the war, etc would by their own natural self interests aid the enemies of the West.
Just like the propaganda war surrounding Gitmo. When Bush was president it was a serious blemish against the West, it would be closed under the new administration. The D's made it a big issue, knowing that Bush could not close it for solids reasons. When Obama D, was elected, for those same solid reasons Bush could not close Gitmo, Obama has not closed Gitmo. Our enemies know that our worse enemy is our own partisan political process. As Pogo said in the '60's, "We have met the enemy and he is us."
I think it is also important to tie this into the rest of the bigger war, the Cold War. Military people think of a military victory or loss, politicians do not ee it that way. The sad part is that the political gains or loss back home are more important than the military gains or loss on the battlefield. Our politicians are very much like what is said about the North Viet-Namese, the did not care how many of their people where killed.
Viet-Nam was decided by our politicians, the NFL where just merely players in that conflict.