That’s why the US ( or Israel) should strike now and not in the fall or the dead of winter.
It is really a messed up situation ....attack Iran, and the world's financial markets start to shimmy like it's 1929. The financial markets would be hit hard, and in the same way that US$80 dollar oil seems like relief now that crude is testing US$140 price-points, US$ 150 oil will seem like a God send compared to whatever levels crude will be at that point. Speculators would drive oil above 200 (at the least), not to mention that no company would insure tankers to pass through the straits of Hormuz.
At the same time, do nothing, and Iran ends up getting some semblance of nuclear capability. This would have severe implications, both direct and indirect. A direct consequence would be Israel having a nation that has nuclear capability, coupled with a stated desire and intent to 'destroy' the Jewish state. Indirect consequences (that I are strangely not mentioned in the media, although i have seen military papers addressing them) would be the domino effect in the middle-east. Saudi Arabia would immediately start pursuing nuclear weapons (if it has not already ....and it does have some IRBMs of Chinese and Pakistani origin that it could potentially use as a delivery system, and it has the cash to get devices from Pakistan or China). The Saudis are not pals with the Iranian Government, and a lot of the weaponry being purchased is anti-Iran specific. What would the Saudis do if Iran got a nuclear weapon, or (if we decide to think small) if Iran started to attack tankers passing by the Straits of Hormuz? Or think about the UAE states (e.g Dubai, Abu Dhabi, etc) ....also buying weapons up the wazoo! Why? And how would they react if Iran, which is opposite from them, started doing things that turn their investment and trade haven into a hell-hole.
Goodness, if Iran was to act the US and Israel may very well have assistance from the UAE and Saudi Arabia.
However, this is a messed up situation either way. Damned if you do, damned if you do not. The question is which level of damnation is the better.
What is fact is that Iran cannot be allowed to garner nuclear weapons technology. That is clear. However, it seems as if Iran really wants it (or is bluffing really well about wanting it), and the question is if the World is ready to do what has to be done, or if the pain of doing so will make them sit and do nothing.
To be honest I sincerely doubt anything will be done. Iran will rattle sabres, the US/Israel will rattle back, and then some months down the line seismic devices will record a subterranean detonation as Iran does its first atomic weapons trial. After that Iran will firmly be in the list of nations that includes Pakistan (and by some respects) North Korea ....nations that will never be touched because they have nukes.
With that said, attacking Iran would lead to fiscal-economic pain beyond belief. But a choice must be made.