One on hand, the Chairman of the Joint Chiefs sez:
"Opening up a third front right now would be extremely stressful for us," referring to the prospect of a direct clash with Iran while fighting continues in Iraq and Afghanistan. "This is a very unstable part of the world, and I don't need it to be more unstable."
On the other, you've got Liz Cheney:
"I think the Iranians have to believe that we will use force if necessary, and I'm concerned because you had statements for a period of time there from people like the commander in Centcom, who has since been relieved, suggesting that force was off the table" ... and she said it is crucial to make Iran realize, "despite what you may be hearing from Congress, despite what you may be hearing from others in the administration who might be saying force isn't on the table, that we're serious." As for an Israeli strike on Iran, she said: "I certainly don't think that we should do anything but support them."
I just wonder who Cheney et. al. think they're fooling. The Iranians know -- maybe better than some of our own policy makers -- the conditions on the ground in Iraq and Afghanistan. They read public statements. Our ability to intervene militarily in Iran is severely constrained by our other commitments. It's not smart policy to try and bluff when your cards are showing.