As always, Stalin's precise motives are "inscrutable" They may well have been "more negative than positive", with Stalin "more anxious to keep other powers out of neighbouring buffer states… than to integrate them." Furthermore, GATT's notion of ostensibly nondiscriminatory treatment of trade partners was thought to be incompatible with notions of socialist solidarity. In any event, proposals for a customs union and economic integration of Central and Eastern Europe date back at least to the Revolutions of 1848 (although many earlier proposals had been intended to stave off the Russian and/or communist "menace") and the state-to-state trading inherent in centrally planned economies required some sort of coordination: otherwise, a monopolist seller would face a monopsonist buyer, with no structure to set prices.