Within hours, Iran is expected to deliver that promised, "telling blow" against "western arrogance." But no one can say (with any certainty) what Tehran has in mind.
This much we know: some sort of major event will occur in Iran tomorrow, in conjunction with the 31st anniversary of the Islamic Revolution. However, it's still largely a guess as to what will transpire; various scholars and analysts have suggested a variety of scenarios, ranging from a harsh crackdown against domestic dissidents; a missile demonstration (or multiple launches), a nuclear test or even a strike against Israel.
At the low end of the spectrum (in terms of probability) is a preemptive attack against the Jewish state. Despite their supposed willingness to become "martyrs for the cause" and strong belief in Islamic mysticism (President Mahmoud Ahmadinejad has reportedly funded a highway project to prepare for the return of the 12th Imam), Iranian leaders have not demonstrated a desire for national suicide.
In other words, any strike by Iran against Israel would be met with a swift and overwhelming response that would deter--or completely end--Tehran's larger ambitions. To be sure, the mullahs and Ahmadeinjad probably view a showdown with Israel as inevitable, but there is no indication they want an immediate confrontation, particularly if Iran has not developed nuclear weapons.
Once Tehran gets the bomb, the equation will change, but only slightly; Israel will maintain an overwhelming nuclear advantage for years to come, with the ability to destroy all of Iran's major population centers--and key military targets--with enough weapons left over for additional strikes, if necessary. It's enough to make any Israeli adversary stop and think--even the crazies in Tehran.
Likewise, the possibility of a near-term Iranian nuclear test is also considered remote. While the existence of an advanced, covert weapons program cannot be ruled out, there is nothing to indicate that Iran has actually developed--and is ready to test--a viable nuclear device. Indeed, Ahmadinejad's recent directive (issued earlier this week) suggests that Iran is only now beginning to enrich uranium at 20% purity. But that's a far step from the 90% level required for weapons-grade material. Tehran could reach that level only months after attaining that intermediary step, but there is no conclusive proof that Iranian scientists have completed the other steps needed to build a nuke, from development of a working trigger mechanism, to actually fabrication of a deliverable device.
It's worth remembering that Tehran could by-pass the final steps in the development process by simply purchasing a nuclear weapon from North Korea. However, Pyongyang's devices have reliability issues, and Iran wants the ability to build its own nukes. Buying--and detonating--a bomb produced in the DPRK would be a tacit admission that Tehran's nuclear program has come up short, and eliminate one of the regime's most effective bargaining chips, the threat to develop nukes. North Korea would also pay a heavy price for aiding the Iranians, at a time when Kim Jong-il can (potentially) cut a favorable deal with the Obama Administration.
But some sources state that Iran does, in fact, have at least one nuclear weapon. According to a recent article in the German newspaper Sueddeutsche Zeitung, a Russian nuclear expert has told the International Atomic Energy Agency that Tehran has developed a nuclear warhead, and is attempting to make it small enough to fit on a Shahab-3 missile--which has the range to hit Israel. Michael Ledeen of Pajamas Media was one of the few western columnists to report that claim, which is supposedly contained in a new IAEA summary, and verified by at least one western intelligence agency. Officially, the U.N. agency has confirmed the presence of foreign scientists in the Iranian nuclear program, but the Russian scientist's claims have not been fully coroborated, at least publicly.
Mr. Ledeen believes a more likely Thursday scenario is a massive government crackdown against the Iranian opposition movement. The leadership in Tehran has grown tired of anti-regime protests, which began after last summer's presidential election. Opposition leaders have publicly stated that a Chinese-style crackdown is expected, and since the mullahs believe that protesters are controlled by the U.S., Israel (and other enemies) a move against them would constitute a blow against the west.
A missile test may also be in the offing. Tehran has never tested the BM-25, an intermediate range system purchased from North Korea more than two years ago. The BM-25 has the ability to strike targets as far away as southern Europe, and a successful test would be a true milestone for Iran and its ballistic missile program. More importantly, the missile can be easily adapted to carry a nuclear warhead (in fact, the original Soviet model was designed for specifically for that purpose). So, Iran reaching an IOC with the BM-25 would represent a blow against the west.
As a final possibility, Tehran might use the revolution's anniversary to duplicate one of its recent space launches. Still, that sort of event wouldn't carry the weight of a major missile test, a "final" campaign against protesters, or (God forbid) a nuclear detonation.
ADDENDUM: U.S. intelligence agencies have been remarkably quiet about what might happen in Iran tomorrow. With that in mind, it would be interesting to know the current whereabouts of Cobra Ball, the Air Force aircraft used to track foreign missile tests, and Constant Phoenix, the platform that collects air samples following underground nuclear detonations. The presence of either aircraft at bases in (or near) the Persian Gulf would offer potential clues regarding our assessment of Iranian plans.