Actually, Pakistan (nuke technology from Abdul Qadeer Khan) and China (through their proxy client North Korea missile components) have played major roles in making Iran nuke capable; however, it is the Russians who have been the major player here and the analogy to the 1962 Cubam Missile Crisis is quite striking. The threat to America and Israel from Iran's nukes is as great or greater than what Castro's threat was in 1962. Why? The Soviets controlled Castro and had full control over the nukes. Russia will not have that kind of control over Iran's nukes--little to none.
I state that the threat is greater from Iran today (near future) than it was from Cuba/Castro in 1962 for this reason.
Khruschev was edgy but he was not a madman like Iran's whacko is.
The common thread is the Russians today in Iran and with Cuba in 1962. The difference is unlike JFK, Bush will not be upfront with the Americans about Russia's role as JFK was about the Soviets' role.
We can't (Our Economy can't) afford to piss off the "Former" USSR and China right now.