The options are negotiate, launch aerial attacks to take out the nuclear program, or to enact regime change through one means or another. Negotiation is not exactly an option Iran has pretty much ruled out any deal that would limit its nuclear weapons program. There is also the fact that the Israelis will not patiently sit by while the Iranians use negotiations to buy time to continue their nuclear weapons development. These two factors leave only the option of stopping the program through air attacks or regime change.
Air attacks have huge problems. Iran has a widely-dispersed nuclear program. There are at least 23 cities (plus uranium mines) in this program. However, targeting does not just involve the nuclear program. Iran also has a huge missile program. There are 40 cities or islands involved with Irans missile program, which also would need to be hit so as to limit or preferably eliminate delivery options for the Iranians. This means at least 63 sites have to be hit in order to guarantee a major disruption to the Iranian nuclear program and its delivery system.
The type of air attack involved would probably be on the order of the first day of the 1991 Gulf War, in which a devastating air attack was launched over a months time. Even that devastating attack was not enough to prevent Saddam Hussein from launching missiles against Israel and Saudi Arabia in the 1991 Gulf War. In 2003, special operations forces were able to prevent a large number of launches, but their use is a huge step forward. Iran has some modern planes (particularly the MiG-29 Fulcrum), but the majority of their aircraft are old F-14As, F-4 Phantoms, J-7 Fishbeds, and F-5E Tigers. An air campaign would be able to hit the sites, and degrade the program. Iranian response would unpredictable, though.
The best option to guarantee a halt to Irans nuclear weapons program is to overthrow the imams. There are two ways this can be done; sponsoring the domestic opposition (which has significant popular support), or through an invasion. The former option has worked in the past. In the 1980s, the CIA was able to keep the Polish Solidarity movement functioning as an opposition movement despite martial law and opposition by the Polish and Russian secret police. That said, the effort took eight years, and the CIA back then was run by William Casey. Todays CIA has become more of a bureaucracy, and much more risk-averse. The other problem with such an effort is that the situation in Iran is markedly different in two respects: Poland did not have a lengthy history of sponsoring terrorist attacks, nor was that country trying to develop nuclear weapons.
The other option is an invasion. This is probably the touchiest option. Currently, Iraq involves 17 American brigades and three division headquarters. Afghanistan involves another division headquarters and three brigades. The 2nd Infantry Division is pretty much committed to defending the Republic of Korea. Two more divisions are carrying out peacekeeping in various parts of the world (the Sinai, Kosovo, and Bosnia being major deployments on that front). This is seven out of 24 divisions available (12 active, 8 National Guard, 3 active Marine, one reserve Marine). The Army is arguably stretched thin, since some divisions will have returned from Iraq or Afghanistan. Until the situation in Iraq stabilizes or additional divisions are formed up, that will remain the case. Iraq has become an insurgency, and those take time (usually five to ten years). Iran would, in all likelihood, develop a similar insurgency. That will further tie down American forces in the region.
The options against Iran are limited, in large part due to the peace dividend of the 1990s, in which eight active-duty and four National Guard divisions were disbanded. What is also not mentioned is that the divisions at the end of the Cold War had more troops per division than they do now. The Air Force and Navy suffered similar cuts (the navy lost over 200 ships, including three carrier battle groups, and the Air Force lost a dozen fighter wings and retired the entire force of FB-111A and B-52G bombers). The peace dividend is proving to be very costly three years into the war on terrorism. Harold C. Hutchison (firstname.lastname@example.org)
Americas Options Against Iran. Irans nuclear program is a matter of concern. The real question, of course, is what can the United States do about it?