Iran and North Korea are almost a nuclear power now. Once getting the nuclear hardware in their hands, the rulers of these countries are bound to be more powerful. And it is not new for them and their other neighbors to use the weapons of mass destruction against their own citizens, too. Recent history is full of such proofs. Even if we rely on their sanity, there are all the possibilities that the hardliner groups operating within these nations and openly supported by their rulers may catch hold of such weapons. At worst they may attack the nuclear plant itself and play an unbelievable havoc. Adequately equipped with rocket launchers and other facilities to destroy targets from a long distance, these radical groups are so powerful there; and security personals have often been proved helplessly weak before them.
There is another side of the coin, too. In modern times, no country should be prevented from taking advantages of the latest technology. Nuclear power plants provide the cheapest energy. If the developing nations are to be kept away from using the nuclear energy, as there is potential danger of using the very facility for producing nuclear warheads, the most developed nations must come forward with helping hands. They should providing alternative sources of energy to these nations.
The nations like Iran and Pakistan (and there are so many, including Israel, in the line) can't be denied the benefits of scientific developments. Nor the sending of western troops would be a solution. Iraq and Afghanistan are examples of such misconceived solutions. These countries have become the largest cemeteries for foreign troops.
To assist them in energy sector would be a preventive measure. Make the economic packages offered to these countries more human and devoid of strategic interests. Instead stamping them as rivals, make them trusting trade partners. It can pave the way for trustful relations. If we wish the mutually assured happiness, then we have to cultivate the exporting of the services and goods only, and not the fighter planes and missiles. It's the only way for our survival; it's the only way left for our survival, perhaps.