With a nuclear umbrella, Tehran would act with even more impunity and guarantee that no effort to quell these crises would ever come to fruition unless it got Iran’s blessing first. Western efforts to bring a modicum of stability to the area and ensure that pro-Western regimes are not toppled would become even more remote. If Iran’s propensity for mischief is so high now, a nuclear-capable Iran would be even more agg­ressive in its ­actions to assert its hege­mony beyond its ­borders.

In the wake of Iran’s ascendance, regional powers would be confronted with tough options. The US nuclear umbrella would not be enough to protect the Gulf States, Saudi Arabia, Egypt and Jordan from Iran’s bullying. Their rulers would have to choose between falling under Tehran’s sphere of influence, or upping the ante and going nuclear themselves. Not that these two options are mutually exclusive — a warming-up to Tehran will no doubt happen if the West fails to confront the Iranian threat effectively as a matter of survival — but the risk of proliferation is very real. Many Middle Eastern countries — 13 at the latest count — are likely to pursue their own nuclear programmes in response to Iran, triggering a nuclear arms race in the Middle East and casting a giant shadow over the oil-rich region.

During the Cold War, the principle of “mutually assured destruction” (MAD) ensured a fragile balance between the West and the Communist bloc. Even then, with just two blocs and lines of communication to fend off crises, MAD could malfunction — as was the case during the Cuban missile crisis. This time, though, with several nuclear powers trying to balance one another, MAD might go mad. There is also the risk that some of the likely proliferators could be toppled by radical Islamic movements or, just as bad, lend a nuclear bomb in a suitcase to non-state actors. Instead of one erratic revolutionary power with nukes, we might soon have several. Can we risk a world where Iran’s warmongering may drive oil prices through the roof? Can we afford a miscalculation that would bring a nuclear winter over the biggest known oil reserves for cent­uries to come?