nukes seem to have not led to war possibly due to theories of mutually assured destruction.

Yeap! absolutely you're right about this one. If North Korea didn't have nukes, they could have been colonized already indirectly, look what happen to Iraq and Libya; they failed to have their own nukes because of fear of sanction, now they have so much chaos in their own country. Iran made the right decision to have their own nukes to serves us an insurance in case theirs any abuse from powerful country.