Sectarian tension between the two mainstream versions of Islam – Sunni and Shia – is one of the enduring threats to world peace. It led to the loss of between half a million and a million lives in the 1980-88 Iran-Iraq war; it is still stoking the bloody conflicts in Syria, Iraq and elsewhere. Against this background, reports that Iran as the major Shia regional power was preparing to arm itself with nuclear weapons were of the utmost concern to the international community. Similarly, relief that this threat has now been averted is equally being felt worldwide – if it really has. The Israeli Government, and its right-wing allies in the United States Congress, deny it trenchantly. “An error of historic proportions” is how Israeli spokesmen characterise th