Have N. Korea and Iran tested? I'm not even 100% sure N. Korea has nukes.
We really have little knowledge of what goes on in Iran and especially N. Korea.
I think recent estimates put them with enough material for 6-7 plutonium and uranium based weapons. I was just reading an article that said we are not sure if they have the ability to deliver or detonate it properly. I am pretty sure that China will tell them anything that they need to know though. Neither country has tested to date as far as I could tell. Iran is well on its way as well and their leader is as screwed up as Kim jong Il. Scary thought. Their facilities are spread out over several dozen locations, some underneath mountains for added protetion. If we strike, we better make sure we get them all. I don't think Iran has the capability to deliver a warhead across the Atlantic via missile, but that doesn't meant they could bring one across our southern border and detonate in the heart of NYC if they wanted to.