It knows that it would face attack by a much more heavily armed Israel, whether supported by the US or not; that Sunni powers in the region could move quickly to counter a “Shia bomb” with their own nuclear weapons; and that additional crushing international sanctions could be imposed. And there is another factor that should not be instantly dismissed, as it usually is by cynical critics: Iranian leaders’ repeated strong rejection of weapons of mass destruction on religious grounds.
伊朗一直对跨越红线所暗含的风险十分警觉。它知道，它将受到武装远比自己强的以色列的攻击（不管有没有美国支持）；它知道，地区中的逊尼派力量可以很快行动起来用它们自身的核武器制造一颗“什叶炸弹”；它知道，它可能面临更加严厉的国际制裁。还有一个不应该轻易忽视的因素——犬儒主义批评家经常忽视它：伊朗领导人出于宗教立场一再拒绝大规模杀伤性武器。