Maybe it's Khomeini.
Yeah, that's Khomeini allright.
Not that he had anything to do with the treaty discussions... on account of being dead since 1989.
The current Ayatollah, confusingly named Khamenei, looks somewhat similar but with one distinct difference - he always wears glasses. Guess the cartoonist got confused.

For the record he didn't have anything to do with the talks either.
EDIT: Let me reword that: as Supreme Ruler of Iran the Ayatollah is obviously involved, what I'm trying to say is that he hasn't involved himself directly. Iran was represented by a negotiation team that the Ayatollah was not part of so he would never have met Kerry. I know that the image is symbolic but it just drives home how wrong it is even further.