accurate observation by satellites, "over the horizon raclarrt and. othel neans 'enabling better warning of attack. There are a].so better possibilities for acquiring and analysing such data, whicb nay proviite nore rapid assessment and possibilities of retargeting of rnissiles during a nuclear e!(change ' hll+. rhese various developments will prowide the super-Pon'ers w-ith significantly enhanced capabilities. Improvements in the accuracy of ballistic missiles rcould increase the effectiveness of a possible first-strike against land-based missile forces. such accuracy might also create the perception that specific targets could be destroyed. with a ninimr:m of collateraL danage ' thus *idening the range of circunstances vhen a nuclear attack could be utilized. \I5. Acquisition of the capabilities discussed. above wilJ- not' however ' make possible ple-enptive strikes against submarine-based nLssiles or a strategic airforce that rnaintains a substantive airborne e.].ert. fhe relative stability of the super-Power nuclear balarrce thus remains, at least for the time being. The developments referred to ill- also be of consequence in other areas of nuclear strategy and this vi11 require review and probabl-y revision of strategic doctrines. The !0oae general consequences, partieularly as they affect gl-obal stability and security, are considered belov. l+t5, rtre developrnent of the capability to engage in nuclear war-fighting and. to Iespond to various levels of attack corpelg a review of the neaning of what a credible deterrent is. Ttre capability to inflict unacceptable levels of da.mage in any State which threatened nucl-ear attack has been regardeal as the essence of nucLear d.eterrence. the capability to launch firnited strikes suggests a series of circumstances, however, where threats of retatlation against population and industry nay not be regarded. as an adequate or credible ?esponse. A super-Pouer may thus not consid.er that it possesses a credible d.eterrent on all Levels unless it has a capacity both for seLective and optional targeting as well as for inflicting