not build then. Reports in recent years that, other States have worked secretfy to acquire nuclear weapons are a cause for concern, but devel-opnents have not so far borne out the early fears of a very rapid. horizontal nuclear proli feration, l+26. The main reason is that a State vilf not develop nuclear weapons sin4>ly because it has the capability to do so. Such a fundamental d.ecision nil-1 be based on other factors, as has been discussed in paragraphs 368-383 above, Nevertheless, general techno.logical developnent as 1,re11 as the increasing reliance internationally on nuclear por+er for generation of electricity is leading to a rise in the number of countries which potentially wou,ld have the capability to develop nuc],ear lreapons. This does not nean that operation of a cortrmercia.l nuclear pover reactor autonaticaLly gives a State the capability to construct a nuclear weapon. The recent Internationa-L Nuclear luel Cycle Evaluation (INFCE) study concludes that fuel cycle facilities are not the nost efficient Toute to acquire materials for the manufacture of nuclear \reapons, ilowever, a State vith a small nuclear industry including an active but not necessarily l"arge research coraponent wil-l- have a reserve of knor'ledge which, if so applied, could be utilized in a programme to deve.lop nuclear weapons . \27. fhe spread of nuclear power has al-so been accompanied by the gradual spread of the sensitive technologies through which fissionable material usable in weapons is obtained - uranium enrichment and reprocessing. With tirne, the ability to make weapon-grad.e nateriaf is probably within the reach of some 15 to 2! cormtries. \28. In response to international requirements for energ:y, '"rorld nuclear por,re" capacity rose from about 1l+,oOO M,fe to more than ?8,000 M^Ie betffeen a97o and 1976. INFCE quotes a figure of 131 ,000 lff,Ie at the end of 1979, and a figure of alnost
**Analysis**
The text discusses the development and spread of nuclear power and the potential for countries to acquire nuclear weapons. It highlights the technological advancements in the field and the potential for more countries to develop the capability to produce nuclear weapons. The text also mentions the international efforts to evaluate the nuclear fuel cycle and the spread of sensitive technologies. Given the focus on nuclear power and the potential for military applications, it is likely that the text is related to Science and Technology.

**Category**
Science and Technology