Exactly... In his memoirs, General Giap admitted that the North Vietnamese Army could have never beaten the US and ARVN forces on the battlefield. He simply had to hold out until the American left and war protestors forced political change, and for the US to abandon the war. Once the US had pulled out of Viet Nam, the north was free to break the agreements they had made, and invade the south. It also allowed the "Killing Fields" of Cambodia to take place, but that's another story.
I believe that you're 100% correct. If the US were attacked again, it would help minimize or even destroy the anti-war efforts here in the US. I mean, look at how even some of the pubbies are surrendering. They realize that all they need to do is wait us out, especially those idiots calling for a "timetable," where once the US pulls out due to political pressure (and failures), and if that happens, they declare that they've beaten the great satan, and we WILL be hit by terrorists, over and over again.
If the US were attacked again, there would be people screaming for action, and our pulling out would disappear from the options on the table. And I pray that one of those options is to get really brutal with them. To actually fight a war how it was meant to be fought: Until the enemy is completely defeated.
Mark
After the war General Giap also pointed out that the North Vietnamese were planning to fight a war against the U.S. that would last for 35 years. The eyes of U.S. officials popped out of their heads when they heard that one -- they knew that the short attention span of the American public (even back then) would never allow for that kind of ordeal.