Among the most significant polemical fall-out of the past year has been the increasing indication that modern weapons questions lie near the heart of Sino-Soviet estrangement. Whether or not the recent Chinese Communist charge is true, that the Russians later reneged on a 1957 “advanced technology” commitment, Soviet and Chinese behaviour since 1957 testifies to considerable Russian long-range concern over a nuclear-armed China, Russian reluctance to assist China to gain this end quickly, and accumulating Chinese anger at such un-comradely behaviour. The only unique ingredient in recent polemical exchanges is added explicitness; the modern weapons messages have been there all along. This is not to say that the Sino-Soviet schism is not the product, as well, of competing revolutionary strategies, theological pretension, struggle for supreme Communist authority, and fundamental disagreement over whether Stalin should be praised or buried. Underlying such antagonisms and contributing to them, however, have been deep-seated differences over modern weapons central to the initiation and aggravation of Sino-Soviet estrangement.