Sentence:  A chief criticism levelled against American "<WSD>lateralist</WSD>" and "polar" theorists is precisely the accusation that they are attempting to avoid the issue of the development of relations between the two socio-economic systems, i.e., the essentially bipolar politico-strategic structure of postwar international relations. 
Meaning of the word marked with <WSD> tags:  Characteristic of lateralism; pertaining to the interactions of opposing interests of equal power.