[en] During the later years the risks of nuclear proliferation have again become a major topic of interest. This is primarily due to the acute problems caused by Iraq, North Korea, and the 3 new states of the former USSR, Ukraine, Kazakhstan and Belarus. Analysis shows that security problems and prestige are the two most important motives, when the risks of proliferation are considered. But motives are not enough. To produce nuclear weapons a number of technological requirements must also be fulfilled. The country must be able to produce almost pure fissile material, i.e. ²³⁵U or ²³⁹Pu. It must also be able to solve a number of metallurgical, explosive, ignition, physics and other problems. These are in particular non-trivial, if a implosion weapon is to be designed. A review is made of the nuclear facilities in a number of the countries which have been suggested as possible future nuclear weapons countries. In particular facilities which can produce almost pure fissile materials, ²³⁵U and ²³⁹Pu, are considered. The possibility of nuclear terrorists have often been discussed in the media. However, it seems very unlikely that even a major terrorist or mafia organization will be able to solve all the weapons design problems, even if they could steal the fissile material. It is finally discussed what can be done to reduce the risk of further nuclear proliferation. Political pressure can be brought to bear on countries outside the NPT to join it, but it can be counter-productive, and sometimes the countries that are able to exert such pressure, are not willing to do so for other political reasons. The problem of countries which are party to the NPT, but which are believed to acquire nuclear weapons capability in violation of the treaty, can be countered by unannounced inspections of non-declared facilities. However, such inspections can only be meaningfully performed if the necessary intelligence is available. (EG)