To my professor-friend in Europe asking a good question from me... here is the answer:

"Just nuclear weapons in the hands of democratizing Russia do not pose the same treat as they did in the hands of the Soviet Union, the weapons of a democratic North Korea would pose no greater danger to the world than if they would be in the hands of democratic South Korea. In the hands of leaders whose power is dependent on people who see war as a last resort, weapons of mass destruction will be a weapon of last resort. But in the hands of leaders whose survival depends on maintaining a constant state of tension, the dangerous these weapons being used directly, or via terrorist proxies, increases enormously."

"To democratic governments, whose power is ultimately dependent on the popular will, peace is always an interest. To undemocratic regimes, peace and war are merely interchangeable methods of subjugation."

Sharansky