For MEB, forever.
" For ourselves, we shall not trouble you with specious pretences- either of how we have a right to our empire because we overthrew the Mede (Soviet Union), or are now attacking you because of wrong that you have done us- and make a long speech which would not be believed; and in return we hope that you, instead of thinking to influence us by saying that you did not join the Lacedaemonians (Putin), although their colonists, or that you have done us no wrong, will aim at what is feasible, holding in view the real sentiments of us both; since you know as well as we do that right, as the world goes, is only in question between equals in power, while the strong do what they can and the weak suffer what they must". Thucydides, Melian Dialogue.
Now that's fancy way of delivering an ultimatum, as to one of the issues of most importance at Senator Hagel's hearing to be confirmed as Secretary of Defense.
There are other issues in his confirmation hearing that are instructive, but Iran is probably as a practical matter at the top of the list, in which Hagel has been criticized severely for wishing to talk directly with Iran.
Churchill talked with Stalin, and said he would represent the Devil well in the House of Commons should the Devil agree to fight Hitler.
Of course, there are some hard feeling towards Iran since the embassy taking, but that was also in 1979, and we paid them back for that in various ways, if they did that in their way too.
Maybe that's just how things have to be, given what they want and what we want.
On the other hand, one can make the argument that there is no real harm, and possibly some good, in talking with anyone, depending of course on what one is trying to accomplish.
Presumably in our case that is some form of modus vivendi with Iran that does not have a nuclear weapons capability.
Right there, note, one could have said nuclear weapon, as opposed to capability, since they are not exactly the same thing. There exists a state widely if very quietly believed to have a capability, but not assembled weapons in deliverable form, if that could also change quickly to should such a powerful state feel the need to do so; not Israel, if it's really obvious, hence the beauty of their as usual subtle strategizing.
On the other end of the spectrum, one could talk with Iran in the fashion of Mr. Blonde, the best Reservoir Dog. Tarantino has two nuclear deterrence situations in his movie, whether he knows it or not, one in Pulp Fiction in the coffee-shop, "Everyone's gonna be Fonzie cool," and in Reservoir Dogs at the end, which alas didn't go very well with everyone pointing a gun (nuclear weapon) at someone.
Mr. Blonde believed more in action than in talk, but did deliver a classic ultimatum to Mr. White, after Mr. White complained about Mr. Blonde shooting everyone in the bank when the cops arrived.
"Are you going to bark little doggie, or are you going to bite?"
Such a contemptuous ultimatum sometimes actually brings peace, as it signals that you actually don't really care too much about what happens, like when he addressed poor cop Marvin, before slicing his ear off, for starters.
"Listen kid, I'm not gonna bullshit you, all right? I don't give a good fuck what you know, or don't know, but I'm gonna torture you anyway, regardless. Not to get information. It's amusing, to me, to torture a cop. You can say anything you want cause I've heard it all before. All you can do is pray for a quick death, which you ain't gonna get. You ever listen to K-Billys Super Sounds of the Seventies? It's my personal favorite."
Now that's not as stylish as the Athenians to the Melians, but sometimes talks like that, or Mr. Blonde style, have their place alas in the relations of states, hardly a new issue, if of course, and only if, one really thought it vital to go the distance with Iran and its nuclear program.