The nuclear emperor has no clothes, contends the latest Adelphi paper from the International Institute for Strategic Studies (IISS), in looking at America's new enthusiasm for ''C3.'' Therefore the West might better concentrate on boosting its conventional rather than its nuclear defense.
This heretical assessment of ''C cubed,'' as it is pronounced - the complex network of military command, control, and communications that would be crucial in directing any war - comes from the pen of Australian National University strategist Desmond Ball.
C3 (or in its full form C3I - the I stands for ''intelligence'') is inherently vulnerable and therefore inadequate to keep superpower nuclear war limited, Dr. Ball says. Any nuclear exchanges on the American-Soviet strategic level (as distinct from, say, a European theater level) are likely to lead to all-out nuclear cataclysm.
This conclusion contradicts the Reagan administration rationale in making C3I one of the top priorities in the strategic package announced in Washington last month.
The Reagan administration contends that its five-year $18 billion program will shore up America's fragile command and control structure to give Washington the ability to conduct graduated nuclear war. According to various scenarios, this would involve making one or a few warning nuclear strikes, waiting for the adversary's presumably limited response, then stepping up one's own response proportionately.
Ball argues in his IISS paper, ''Can nuclear war be controlled?'' that any such scenario is nonsense. Even a well-functioning, redundant command and control system would be vulnerable to early disruption or destruction - and in a wartime situation there would thus be enormous pressure to use these facilities before they were lost to launch all-out (rather than limited) nuclear strikes.
The presumption that the superpowers could, in fact, conduct a discriminating nuclear war has implicitly underlain American nuclear strategy ever since the US abandoned John Foster Dulles's ''massive retaliation'' 20 years ago. More particularly, it has underlain the whole 1980 election argument about a ''window of (US) vulnerability'' and the late 1970s shift of focus by strategic thinkers away from nuclear ''deterrence'' (war prevention) to nuclear ''war fighting'' (what happens after war breaks out).
C3I has long been regarded by military planners as the weakest link in the strategic chain. Yet it has never been regarded as invalidating the whole notion of ''controlled escalation'' that Ball calls ''the central operational concept in current US strategic doctrine.'' It has always been assumed that C3I could be improved to the point of making the various American scenarios workable.
Now Ball - one of the most knowledgeable experts writing for the public today on the interplay of weapons technology and nuclear strategy - has mounted a frontal assault on this assumption.
In capsule form Ball's argument is that:
1. The US nuclear command and control system (like the Soviet system) is an uncoordinated hodgepodge that is unsuited to conduct, moderate, or end nuclear war.
2. The command and control system is inherently vulnerable to jamming, spoofing (sending spurious signals), or destruction, and no amount of hardening of facilities can alter this fact.
3. It would in any case take two to keep a nuclear war limited, and Soviet military doctrine has shown no interest in such a concept.
4. The likelihood that the US could keep a superpower nuclear war limited is therefore remote.
The heart of Ball's reasoning is technological rather than theoretical. And the crux of his technological reasoning is the nonsurvivability of C3I in any nuclear exchange.
C3I, because it depends on establishing communications between two or more points around the globe, generally requires ''large, fixed, and soft'' facilities that are easy to destroy, Ball points out.
Radars must generally stay in place, and are easy to knock out. Even superhardened command centers are as vulnerable to a direct hit - given today's accuracies - as are any fixed targets. And airborne command centers - which are now deemed the only survivable solution - are limited to some three days' use by crew fatigue, engine oil depletion, and probable destruction of landing fields.
Ball's ultimate conclusion from all this: ''Limited'' strategic nuclear war would be so uncontrollable that ''decisionmakers would be deterred from initiating nuclear strikes no matter how limited or selective the options available to them.''
This, in turn, requires that more attention be paid to ''another means satisfying the objectives that limited nuclear options are intended to meet'' - i.e., ''conventional deterrence.''
(Adelphi paper No. 169, ''Can nuclear war be controlled?'' by Desmond Ball, is available for (STR)2 ($5) from the International Institute for Strategic Studies, 23 Tavistock St., London WC2E 7NQ.) m