President Obama had been doing an admirable job in recent weeks of keeping the chances of war with Iran from rising, notably in rebuffing Bibi Netanyahu's efforts to get America to lower the threshold for a military attack. But on Friday the chances of war rose, and that's Obama's fault.

A government official said the U.S. will remove the "terrorist" label from the Mujahedin-e Khalq, or MEK, a group that got onto the list of terrorist organizations decades ago by, among other things, killing Americans. I've argued before that such a "delisting" of MEK would empower hardliners in Iran who want to block a negotiated solution of the nuclear issue. After all, not only is MEK devoted to overthrowing the Iranian government, and not only did it side with Saddam Hussein during the Iran-Iraq war--MEK has recently, according to NBC News , served as Israel's proxy in murdering Iranian scientists. So America's delisting of MEK will be used by Iranian hardliners as evidence that America is too hostile to be a reliable negotiating partner--just as American hawks highlight evidence of Iranian hostility to argue that negotiations are futile.

Of course, my argument could be wrong. (Hard to believe, I know!) But last night on Twitter I elicited the opinion of someone who knows much more than I do about Iranian politics--Bahman Kalbasi, a correspondent for BBC Persia. Discussing the prospects for compromises by America and Iran that could lead to a resolution of the nuclear issue, he wrote, in two consecutive tweets, "Compromise is possible, but powerful elements in Iran benefit from the tensions. Delisting gives those elements the upper hand to block such compromise."