He should read Kipling's poem Et Donat Ferentes.
Slow to respond worked in the '40's, '50's and 60's. But now, with both nuclear weapons and the means for delivery proliferating among unstable regimes, we ain't got time to screw around!
I am convinced that Iran is doing what the US did in the 1960's - concurrant engineering of both a nuclear weapon and a delivery system that would carry it.
We had no idea how small the bomb had to be to be carried on an ICBM...we had no idea how big the ICBM had to be to carry a bomb. We developed both concurrantly - expensive, messy, but quicker than doing it serially.
Iran has, last I heard, around 50 nuclear research sites. Probably a bunch more missile development sites. They are not just developing a nuke - they are developing a "weaponized" nuke that their missles can carry - right out of the box.
You won't see Iran go through a testing program. The first test blast will be over Tel Aviv. The next....take your pick; over Brussels, Baghdad, or Ryihad.
As Churchill used to say...."Action - this day!"