MPEPIL has articles on (for example) Marxism, Cold War, and Peaceful Co-existence. Sometimes sections within articles - eg Brezhnev Doctrine - may be helpful. The print copy of this Encyclopedia is at Internat 500 E56c, but as the online version is being consequently updated, holders of an Oxford SSO are advised to consult MPEPIL via the link below.
Russian Approaches to International Law by Some commentary/analysis on USSR/Russian PIL - oldest to newest...
Theory of International Law (Teorii͡a mezhdunarodnogo prava) by 
The Soviet concept of 'limited sovereignty' from Lenin to Gorbachev : the Brezhnev doctrine by 
The Legal Dimension in Cold-War Interactions by Sovetskiĭ ezhegodnik mezhdunarodnogo prava = Soviet year-book of international law 1958-1993
in the Law Bod at Internat 300 S80