It is difficult for the modern, secular West to comprehend the mindset of the Iranian mullahs. We think - or so we like to assume - rationally. So even when the International Atomic Energy Authority produces a report which provides near certain proof that the Iranians are engaged in the construction of a nuclear weapon, a widely shared reaction has been a metaphorical shoulder shrug.
"They would never use it", seems to be the general thought. "It would simply balance out Israel's weapons". This is as profound a mistake as it is possible to make.
It may not seem remotely realistic that an entire nation could be wiped from the map as a matter of policy; but that is what the Iranians see as a legitimate goal of policy. It is not as if they keep it secret. Our failure to grasp this and take any worthwhile action has enabled Iran to make great progress towards acquiring its weapon.
The longer we go on without properly understanding the Iranian regime and its intentions, the more certain we make it that we will eventually be confronted with those intentions.