This is not just another Vietnam: it is much bigger. Vietnam was of no real strategic significance to the US; that is why "losing" it didn't matter, aside from bruised American egos.

Iraq is of tremendous strategic significance, and everyone knows that. Losing it would demonstrate to the world that the US is no longer able to effectively "project power" into the Middle East, where most of the world's oil is. And there are a number of autocratic Arab regimes, such as Saudi Arabia's, that depend on US power for their existence.

The US effort in Vietnam was predicated on the domino theory, which was a chimera. The US effort in Iraq is predicated on oil, which is very real.

The American economy is hollowed out. The US no longer has anything to sell to the rest of the world, aside from high fructose corn syrup and weapons. It depends on the rest of the world for oil and manufactured goods, but the rest of the world has no need for it, as Emmanuel Todd has pointed out. When it comes to having influence in the world, America has put all of its eggs in its military basket. Thus, as far as the rest of the world is concerned, without its military power (and its entertainment industry), America is nothing. That is why military defeat in Iraq would be a disaster for the US.

A bomb, H bomb, Minuteman / The names get more attractive / The decisions are made by NATO / The press call it British opinion -- The Three Johns