nuclear-weapon States" and in par-ticulax the two super-Powers r have withhcld their participation in the work of the Group of Experts. fhe Chairman of the Group has nevertheless kept the super-Powers inforued. of the p"eparation of this report. 7" One basic difficulty in the work on this report has been the absence, in many casese of offieially availabl-e data on nuclear weapons and xelated questions" fn consequence the Croup has in several- instances relied on other avail-able d-ata' in each instance providing the relevs.nt ?eference in order to facil-itate for the reader an understsJrding of the factua^l basis of the report. B" The present report is organized in eight chapters. Chapters If to fV are of a technical nature and refer to existing and future nuclear-weapon capabilities as irel] as the effects of nucfea.r veapons. Chapter V to VII eontain a description and aralyses of the inplications for security and. tlisarnament of the development of nucl-ear weapons as rreu. as the d-octrines for their use" A concluding sulnuary appears in chapter VIII. ;\ppendix I contains o tcchrlica-l. descrirtion of nuclcar- weapon effects, anrJ" appendix rI sets forth "Security assurances" by the nuclear- weapon States as presented to the Conmittee on Disarmanent in 19{J0.Al 35 / lr? .i, L.':. t':1i r.)rii.rc,Lil CHAPTER I] I'ACTUAL I1IFORMATIO1I ON PRESII,T I\\JCI,EA]I ARSENAI,S 9. The exact number of nuclear warheads in the vorld today is probably not knoun by any single person or institution ' and estinates cannot be verified officially. Published figures indicate " however, that the total nay be in excess of l+0,000. fn explosive power these warheads are reported to ralge from about :1.00 tous up to nore than 20 niuion tons equiva.lent of chenical high explosive. The largest weapon evex tested refeased an energy approximately 4,000 +.imes that
**Analysis**
The text appears to be discussing the technical aspects of nuclear weapons, including their effects, capabilities, and implications for security and disarmament. The language used is formal and technical, suggesting a report or document written by experts in the field. The text does not mention economic development, natural resources, or environmental issues, but rather focuses on the military and political aspects of nuclear weapons.

**Category**
Science and technology, International relations