I would put forward a proposition.....
No one can understand why, if they are on the point of developing a nuclear weapon, Iran would instigate a war a war in which it could be destroyed.
However. Consider if, through whatever sources, they have 1 or 2 warheads already available, and can claim to use them in self defence.
I'll leave the target list open, I can think of many.
The current Gulf status quo would be destroyed forever, the oil price would go through the roof, and the European/American influence in the region would disappear....
Sources? Ignoring their own, imminent stocks, Pakistan, N. Korea and other areas could have provided the required material. Unusable until their own weapons were imminent.
Just saying.......