FDL has a nice post that hammers home the insanity of even talking about "glassing" Iran.

First: bombing a country is a declaration of war and Iran will react to it as such. To meaningfully damage the Iranian nuclear effort will require massive bombing. This isn’t one pinpoint attack. Oil will soar to $150 a barrel or so, your economy will crater, so will everyone else’s, your allies will abandon you and you will be all by yourselves. And people won't blame the Iranians, they will blame you.