At this point, it's worth repeating something retired U.S. Colonel Sam Gardiner said last year (via the now sadly defunct Whiskey Bar).

When I discuss the possibility of an American military strike on Iran with my European friends, they invariably point out that an armed confrontation does not make sense -- that it would be unlikely to yield any of the results that American policymakers do want, and that it would be highly likely to yield results that they do not. I tell them they cannot understand U.S. policy if they insist on passing options through that filter. The "making sense" filter was not applied over the past four years for Iraq, and it is unlikely to be applied in evaluating whether to attack Iran.
- The End of the "Summer of Diplomacy" (pdf)