Do you think the physics of nukes is widely shared, accurately?

What nukes? They aren't all the same, and plain old fission bombs are not actually that complicated. Iran is also an ally of Russia and North Korea, both of which have been in the nuclear club for quite some time now. Fusion bombs are a hell of a lot more complicated. Getting optimum yields from either is complicated. There are no secrets at this point about how to make a minimally functional (as used in Japan) fission bomb.

And as far as MAD... Do you think Israel has ever been inspected?

Israel doesn't even admit to having them. They don't need them for MAD. Israel's promise of overwhelming retaliation comes from it's alliance with the US. They have nukes because they want the option. If the US ever abandoned Israel, I guarantee they would let the world know they have them, and they would do a test, or they would have someone inspect them, just like every other nuclear power did before using them as a deterrent.

Right now, the intelligence community doesn't think they're close to a bomb. If that opinion were reversed, that's just as good as having a bomb.

Or it's an invitation to be bombed and/or invaded before they get there.