HOWEVER, an Iranian base in Venezuela is serious business, from the point of view of the US gov.
And a permanent US military presence in Iraq is serious from Iran's point of view.
so the US is quite likely to seek a made-up confrontation with Iran, so they can say, "they hit us !".
and there is always the possibility of Iran doing what nations do naturally - defending themselves against US & Israeli incursions into their territory that are going on all the time.
Ya, that's a common scenario for starting a conflict, though it'd be hard to use an attack on forces on their soil to justify an attack (remember the Gulf of Tonkin attacks you cited were described as occurring in international waters, though apparently the one that happened was in North Vietnamese waters - against a US escort of South Vietnamese terrorists trained by the US entering North Vietnam).
But remember the accidental US downing of an Iranian civilian passenger jet.
How would the US respond to Iranian ships off the US coast accidentally downing a US civilian passenger jet?
I'm less suspicious of a false flag operation - with all the investigation that can debunk it today - than of provocation.
Wasn't the crippling of their nuclear power program an 'act of war'?
But there's a big question that the US wants a war with Iran. Not much doubt there was some interest in the Bush administration; they didn't do it. And it's gotten a lot more 'unattractive' now; also, with trends suggesting the ruling regime is in more and more trouble from their own people - and even more with the Arab uprisings - it'd seem far more likely for us to look how to help the internal opposition that have a war. (something we've done before, of course, in 1953).