A lot people at the time did not think Vietnam strategically important. The whole "Domino" theory was a rationalization for why it was worth fighting over an otherwise unimportant nation. Oh I'm sure the people who advanced it were sincere, but they also had all these theories about how to win wars with airpower, and minimal numbers of ground troops that they wanted to test.
Wait, how did this become about the Domino Theory? I wasn't invoking it or talking about whether Vietnam was worth fighting over. I was talking about the potential for disaster that war posed (not who won/lost South Vietnam).
Al Gore said Iraq is the worst strategic mistake in our history. Gud originally questioned that. You countered that the middle east is much more strategically important than Southeast Asia. Gud said, "From a strategic standpoint a disaster in the Middle East trumps a disaster in Southeast Asia."
You're both right right now, but that wasn't the case then -- not because of the Domino Theory, but because of the century and a half of conflict in Asian/Western and Asian/Asian conflict, in Asia, prior to the Vietnam War. Highlights include: the Opium Wars; the Franco-Chinese war; the first Chinese-Japan War; the Boxer Rebellion; the cultural revolution; warlord rule; WWI; the second Chinese-Japan War; WWII.
Think about all the nations that had a dog in the fight in Vietnam besides the US and Vietnam, itself: the USSR; China; South Korea; North Korea; Australia and NZ; France, Thailand, the Phillipines.
The Vietnam War happened in a powder keg, and so much of it was a cock-of-the-walk fight between the US and the USSR. A new war any place in Asia, so soon after WWII and Korea, had the potential to kick off a third world war, just as a war (right now) in the middle east, has the potential to kick off a third world war. We're lucky we got out of Vietnam, without one.
Gud was right to question Gore's statement, not because Iraq isn't a mistake and isn't a huge stinky morass, but because we don't yet have the perspective of history on Iraq, to decide whether our involvement in Iraq is the worst mistake in our history to date. The disaster that was the Vietnam war, in that time and place, had the potential to end up a worldwide disaster, much as the diaster that is the Iraq war has, in this time and place, the potential to end up a worldwide disaster.
Iraq feels bigger now, because stuff in the now always feels big.