Iran's recent restart of its uranium enrichment program again raises the specter of military action, be it American, Israeli, combined American-Israeli, or in the abstract, European. Can a military operation be successful, and who has the capability to execute it? Good questions. Let's assume for the sake of argument that the option of military action has been selected.
First, it is important to define the objective of any military action. That will determine what and how military assets are used. I think it is a fair assumption that no one is seriously considering the actual invasion of Iran to remove the present regime. It is also safe to assume that no one is contemplating the use of large conventional ground force formations to defeat the Iranian military. The goal of this operation would be to cripple Iran's suspected nascent nuclear weapons program. The most viable option is the use of aerial-delivered munitions and possibly the introduction of special operations forces.
Assuming that the goal is to cripple the Iranian nuclear program, I think that will be difficult - not impossible, but certainly difficult. The Iranians are a smart and resourceful people. Like the rest of the world, they saw what the Israeli Air Force did to Iraq's French-supplied Osirak nuclear reactor outside Baghdad at At-Tuwaythah in June 1981. In one air raid, the Israelis virtually brought the Iraqi nuclear program to a halt. It would have taken years for the Iraqis to reconstitute this critical element of their nuclear weapons effort.
Unlike the Iranians, the Iraqis had placed their eggs in one basket - the core part of the Iraqi program was located in one place, above ground, in a lightly defended area. Conversely, the Iranians have dispersed their program facilities over much of the country, mostly underground or least somewhat buried. Many of the facilities are protected by recently-acquired state-of-the-art Russian air defense systems, or at the least, aging Shah-era (but still capable) American-supplied air defense systems.
An air attack on Iran's nuclear facilities would have to strike multiple hardened or semi-hardened targets over a widespread area. Even if we know where the facilities are, getting them all will be difficult. Could we or the Israelis do it? The Israelis have the talent and I am sure at least the same intelligence we have. Of course, in the post Iraq-WMD (weapons of mass destruction) era, that raises the question: is the intelligence accurate?
As a Middle East specialist/intelligence officer, I focused on this area for almost three decades. I am fairly confident that we have adequate imagery intelligence on the facilities we know about. I can't really speak to the signals intelligence - I have been out of that business too long. As for the human intelligence, unless things have changed since I retired, Iran remains one of the most difficult targets, even tougher than the Iraqi target.
For argument's sake, let's assume the intelligence is accurate. How would we cripple the Iranian program most effectively? The usual first answers are "the Israelis will do it" or "the U.S. military would do it, if they were not already fully engaged fighting counterinsurgencies in both Iraq and Afghanistan."
Let's look at the Israeli options. The option is not a good one. I doubt the Israeli Air Force can project enough power that far from home base. They can certainly project limited power that far (as evidenced by their strike on Palestine Liberation Organization headquarters in Tunis in 1985) or massive power to neighboring countries, but Iran is probably two countries too far for this size of an operation. Israel's best (and only realistic) option is get overflight permission from Turkey, a country with whom they have a long-standing defense cooperation agreement. Given Turkish sensitivity to Iranian, Arab and other Muslim public opinion, I doubt that Turkey would cooperate in this instance. If, and I stress the word, Israel gets overflight permission from Ankara, the complexity of this type of operation will require concentration on limited targets, choosing the most critical piece of the Iranian program and destroying that. It is not a good option, but the leaders in Tel Aviv may regard the Iranian program as a serious enough threat to try it anyway.
As for American capabilities, we come back to the common argument that the U.S. military is already fully engaged, fighting counterinsurgencies in both Iraq and Afghanistan. On the surface this may be true, but if you consider the different resources of the American armed forces, you will find that the U.S. Army and U.S. Marine Corps are bearing the brunt of the commitment to operations in those two theaters. The two services that that will be the main force behind any operations against Iran, the U.S. Air Force and the U.S. Navy, currently are relatively unencumbered and capable of offensive operations on the scale required.
Again, if the intelligence is accurate, the U.S. Air Force and U.S. Navy have the means to cripple the Iranian program if ordered to do so. Let's examine some of the possibilities. The USAF could use Iraqi air bases, but I doubt we would get permission from the Iraqi government - the Shi'a-dominated Iraqi government is not inclined to antagonize Shi'a Iran. Using air bases in any of the Gulf countries or the central Asian republics (that have supported U.S. operations in Afghanistan) is equally implausible. While these are definite limitations, they are not show-stoppers. Over the years, the Air Force and Navy have developed a family of weapons that do not rely on host nations for support. The Air Force's long-range air launched cruise missiles can be fired from aircraft flying from the United States. The Navy can fire sea launched Tomahawks from international waters. Can these stand-off weapons deliver the punch needed? Probably not alone. However, when combined with stealth-capable bombers delivering precision guided munitions against a series of targets across Iran, the objective of the operation can be achieved. Remember - we are not trying to topple the regime in Tehran, merely cripple its nuclear program. We are not trying to defeat them - we are trying to modify their behavior.
In the best of all worlds, it will not come to this. However, I am certain that somewhere in the bowels of the Pentagon, just this kind of planning is already taking place - just in case.