There has been much speculation in the media about the possibility of military action against Iran in response to its refusal to stop enriching uranium outside of International Atomic Energy Agency (IAEA) safeguards.
Israel has stated that it will not permit Iran to develop nuclear weapons. In 1981, the Israeli air force attacked Iraq's nuclear Osirak reactor outside Baghdad. Although they may not have the wherewithal to attack the dispersed Iranian facilities, they may try, or the United States may exercise the military option. See my earlier piece, "Iran - Military Options?"
Of course, we all hope that the military option in not necessary, that Iran will again adhere to international agreements, protocols and norms in its legal nuclear research program. If that happens, I believe political change will come in time. I have always believed and stated that the Islamic Republic, if left to its own devices, will implode and then remove the Islamists. The problem is complicated by their nuclear program. If they continue to act outside international agreements, then the West (probably the United States) will have to act. Of course, a strike may rally the people around the current government, popular or not.
I think much of the impact will depend on who conducts the strike. If the Israelis try, it will have serious repercussions throughout the region, as it will be cast not only in a nationalist light, but also in the religious. I think it will galvanize not only the Arab countries, but the Muslim nations as well. Not that many of them have great relations with Israel, but if the Turks are offended, they may cancel the defense arrangement they have with Tel Aviv.
There is also the possibility that Iran will retaliate by encouraging Hizballah to attack northern Israel - after all, they have supplied Hizballah with the rockets for just such an eventuality. They could also energize an uptick in the tempo of attacks by their other supported organizations, Islamic Jihad (PIJ) and Hamas, although ironically, Hamas's recent victory in the legislative elections might rein them in somewhat.
As I have said, though, I don't think the Israelis have the wherewithal to effectively do this. I think if there is an air strike, it will be done by the United States, specifically, the U.S. Air Force and U.S. Navy utilizing stealth aircraft and long-range missiles.
Assuming the United States conducts a series of strikes, the reaction will depend on who backed the operation. If it is backed by the EU-3 (the United Kingdom, France and Germany) backing, there will cause a rift in the diplomatic relations between Tehran and the European capitals.
Will there be a reaction in the Arab world? Probably a lot of noise, but I doubt there is any Arab country, with the possible exception of Syria, that wants the Iranians to have a nuclear weapon. Regardless of what they all think of the West, Arab-Persian animosity goes back as far as time itself.
The big question is will a strike achieve the aim? The aim, of course, will be to change their behavior. Although it will certainly steel their resolve, the destruction of key portions of their expensive nuclear program, if cast as a multilateral effort and not just the United States, has got to send a powerful message.
If the United States resorts to the military option, it must be done with sufficient (overwhelming) force so that they look around after the earth stops shaking and realize just who they are dealing with.