Well, you have every right to your opinion. But I am one American that believes our Military with the backing and support of the American people could have stomped North Vietnam (throw in a couple other countries) and still come out on top.
They didn't have the back-up, supplies, support ect, and our troops today will tell you so. They would have fought to the last man, no matter how tenacous the VC thought they were. No offence.
Like you said, everyone is welcome to their opinion.