Many things relating to nuclear proliferation have changed since the collapse of the Soviet Union. From the declared nuclear powers, to worldwide tensions and so-called "Hot Spots", the nuclear situation has changed dramatically over the years. Some would say that the threat of a nuclear war has gone down in today's post Soviet society. They are, of course, wrong. The threat of a nuclear war is greater now that the cold war is over because, more nations have nuclear warheads, the smuggling of nuclear materials is on the rise, and nuclear treaties are ineffective.
Many nations have nuclear warheads. While this could be construed as a bad thing, many nuclear powers do not adhere to the old "us and them" theory. It is no longer a fight between the communist and capitalist societies. While more nations have the technology to make nuclear warheads, many do not due to political pressure. The most common reason for the development of nuclear warheads is to prove a said nation's ability to do so. For example, South Africa developed the technology to produce nuclear missiles, and then dismantled them. (1) In doing so it became the first nation to voluntarily giving up its nuclear missiles. In other cases the nuclear material from certain countries is in the process of being removed. A U.S.- sponsored program to secure nuclear components in the former Soviet Union has locked up a third of an estimated 600 tons of weapons-usable material. (5) In this case the material was left behind, poorly secured, when the Soviet Union collapsed. In addition, the wide spread proliferation of nuclear warheads has created a worldwide nuclear deterrence. (3) The risk of world destruction is more emphasized now, despite the fact that it existed during the cold war.
Rogue nations have upset the balance of power. The mutual deterrence that existed during the cold war, because instead of two parties fighting for the world you now have numerous parties trying to defend their own interests inside of their own area.