stockpile. StiI.I, as long as nuclear veapons exist, there voul-d. be pressures for changes in the stockpiles that may require nuclear-weapon testing. 92" Fronx the discussion above ? one may conclud,e that a comprehensive test ban woutd. make rnore d.ifficult the continued d.evelopment of sophisticated weapons vithin the established. nuclear powers and thus have an inhibiting effect on the arns race. A comprehensive test bsn wou.1d slso have va.1ue in preventing horizontaf proliferat ion: it wou1d, in particular, reinforce the political connitnent to non-proliferat ion und.ertaken by States Parties to the Treaty on the Non-Pro1i ferat ion of Nuclear Weapons. It nay be technicalty possible for many States to develop unsophisticated fission veapons a,tld- to have some confidence in their rel-iability, vithout carrying out a test. It is unl-ikel-y, however, that States r^rould ldsh to commit their national security for any length of time to nuclear-\^reapon systems that are untested.. Development of advanced systems such as thermo-nucl-ean weapons or systems w:ith strict uilitary specifications vould be, accord.ing to accepted engineering connon sense, very uncertain if testing was not rossible" Part of the test-ban discussion has focused on lowerins the present^/35/392English Annex rafie 4u threshold of 150 kt., vhich iloes not seem to have had any strong attenuatinginfluence on the technological aleveLopment of nuc].ear veapons. D. General coments on lreapon systems 93" Any noalern veapon system consists of several" naJor components in ad.d.ition to the lrarhead.. Such components are the vehiele (..g. " nissile) vhich carries the varhead to the target i the pJ-atforn (e,9. a subnarine or a siJ.o) fron t'hich the vehicle is launched; the coDnand, control and coDmunications equipnent by which the systen is activated o and, in sone cases, directed; and. the particular means of intelligence that give the signaJ. for its activation. A-l-1 or some of these