Suppose it is true not only that the Soviets are responsible for the use of chemical and biological weapons in Afghanistan and Southeast Asia, but also that the assassination attempt on the pope was undertaken with their blessing--what is the implication for U.S.-Soviet relations? What should the American response be? McGeorge Bundy addressed this question in our pages on Jan. 9. The following is the response of Malcolm Toon, former American ambassador to the Soviet Union.

The Soviet disinformation campaign to prove to the world that the new Soviet party leader, Yuri Andropov, despite his KGB affiliation, is really a nice fellow and even a closet liberal has run into serious trouble as the evidence of recent Soviet misbehavior accumulates. There now seems no question that the Soviets have been testing their chemical and biological warfare resources and techniques on the beleaguered but still undaunted Afghan rebels as well as on innocent noncombattants in Southeast Asia. More recently, the news from Rome fuels and reinforces the suspicion that there was a Bulgarian--and thus Soviet--connection with the attempted assassination of Pope John Paul II.

My imputation of guilt to Moscow will raise few eyebrows among those knowledgeable about the subservient relationship between the Bulgarians and their Soviet masters. Clearly, if the Bulgarian secret services were involved, then the KGB was also involved. For, certainly, the Bulgarians would not on their own engage in such a reckless, sensitive, highly explosive mission. And, equally certainly, if the KGB was involved, then its chief at the time--Yuri Andropov--must have had specific knowledge of and given his personal approval to the assassination attempt.

But the jury is still out, and it would be premature at this point to pin the blame for fingering the respected and revered Pope John Paul II for assassination. But the possiblilty is there, and it is not too soon to consider what our course of action should be in the event our Italian friends should prove beyond a doubt the Bulgarian connection. By "our," I have in mind not only the official position in Washington but also the collective reaction of the NATO family.

It may boggle the minds of some that the Soviets of their satraps would engage in such an obscentity, but not of those who down through the years have carefully monitored and recorded repeated examples of Soviet brutality -- from the ruthless liquidation of the Russian peasantry in the '20s through the pruges of all possible sources of opposition to the leadership in the '30s to the more recent brutal treatment of dissidents and refuseniks by Andropov's KGB in the '70s. So, it is entirely possible that the evidence, when in, will be conclusive of Bulgarian and, therefore, Soviet guilt, and we better gear ourselves now to deal with this highly explosive issue.

Some will recommend that we sever all ties with a nation capable of such contemptible behavior. That would be an egregious mistake. Others, apprehensive of the consequence for world stability of making a pariah of the Soviet Union, may suggest that we, in effect, sweep the whole dirty affair under the rug and thus avoid any serious impairment of our relations with Moscow. That, in my view, would be an equally unacceptable and perhaps even a worse mistake. Our most sensible course of action, it seems to me, would be not to outlaw the Soviet Union, equally not to ignore the facts, but to recast our relationsip to reflect newly revealed realities.I would suggest the following specific steps:

1) Characterize the Soviet Union for what it is -- a ruthless, brutal power capable of resorting to the worst obscenities to meet its ends, but a power possessing such awesome military might that, if isolated and deprived of intercourse with the civilized world, could well make a serious misjudgment and upset the fragile balance that now exists between peace and Armageddon.

2) Maintain formal ties with the Soviet Union, continue efforts together with our allies to achieve a more stable world by defusing or at least making less volatile the areas of tension between us, capping the arms race and, one hopes, in the end inducing less obnoxious Soviet behavior on the world scene.

3) Modify our traditional relationship with the Soviets to reflect realities -- always there but ignored during eras of "good feeling." This means, above all, the elimination of all traces of chuminess and final recognition that Soviet ideology and behavior simply rule out camaraderie, good will and trust between us.

4) Terminate all references to summitry as a desirable way of doing business with the Soviets. The president should make clear that, in the light of recent evidence, a meeting with Andropov would unacceptably tarnish the luster of the high office he holds and that from now on he will deal with the Soviets through our ambassador in Moscow and occasional meetings at the foreign minister level, if these should offer some prospect of forward movement.

5) Urge the private sector to reduce to a minimum or, better, terminate the successors to Pugwash -- such as the Dartmouth conference, the United Nations Association meetings and others that have always suffered from the asymmetry between critics of policies of an incumbent American administration and staunch protagonists and defenders of Soviet positions and behavior.

6) Persuade our media to refrain from offering free propaganda platforms to the self-styled "independents" on the Soviet side -- like the Arbatovs, the Zhukovs and the Menshikovs, who are far from being what they pretend to be.

7) Make clear there is a price for performing dirty tricks at Soviet behest by reducing to a minimum traffic with the Bulgarians -- meaning, among other things, cutting Western representation in Sofia to the bone -- e.g., closing all but one or two NATO embassies.

8) Consult on all of the above with our NATO allies to ensure a concerted allied reaction and thus avoid shameful and damaging spectables of disarray such as we saw in the unseemly hassle over the pipeline.