How MAD can they be?

EVEN if Iran got the bomb, it would know that Israel had one too, and that knowledge would deter both countries from using their weapons, just as the doctrine of “Mutual Assured Destruction” kept America and the Soviet Union at peace during the cold war. That is the soothing assumption of those who say Israel can live with a nuclear Iran. Is it correct?

In the cold war, the foes were both big countries with big populations. But at 65m Iran's population is ten times bigger than Israel's, and Iran is 80 times bigger. In 2001 Ayatollah Akbar Hashemi Rafsanjani, Iran's once and perhaps future president, mused ominously in a Friday sermon that “an atomic bomb would not leave anything in Israel, but the same thing would just produce damage in the Muslim world”.

This lack of symmetry may be more apparent than real. Israel is reckoned to have around 200 nuclear warheads, more than enough to destroy all Iran's towns and cities. Some strategists argue that tiny Israel could be disabled by a first strike. But to prevent any Israeli retaliation, an Iranian attack would not only have to overcome Israel's Arrow air-defence missiles and destroy its airfields but also penetrate the silos of its nuclear-tipped Jericho missiles. In recent years, moreover, Israel is rumoured to have put nuclear cruise missiles on board its three Dolphin submarines.

In contemplating an attack on Israel, Iran would have also to weigh the (possibly nuclear) reaction of the United States. “In the event of any attack on Israel,” George Bush said last May, “the United States will come to Israel's aid.” If Iran got the bomb, America might formalise this promise―and maybe put an umbrella of “extended deterrence” over other American allies in the region.