How long could the Soviet Union have kept going under the Stalinist system before some sort of internal collapse/massive reform/World War III? Say Stalin kicks the bucket in '53 as in OTL, how long could a Stalinist successor (Molotov, Kaganovich, Voroshilov, etc.) keep up the system--Politically, militarily, and economically? Obviously the Joseph Vissarionovich's personality cult will take a hit, but we've seen how long they've been able to keep the Mao cult alive, so...