It may seem unnecessary, if not useless, to analyse two supposedly close allies in their common struggle against the ‘imperialist westerner’. In this paper, I shall contest the idea that the communist world was not united as one. I even further argue, based on the ‘Neo-Classical Realism’ approach that such a bloc had never existed and will never exist. I believe that each and every country, whatever its official ideology or institutional regime, is necessarily turned into the fulfillment of its own interest. The further remaining elements and/or factors shall be used, to fulfill its own national interests. People’s Republic of China is not much different from my analytical perspective. I shall try to demonstrate in this paper that P.R.C. corresponds to the theoretical approach I utilised in order to explain P.R.C.’s foreign policy behaviour. Indeed, P.R.C.’s foreign policy behaviour is the perfect illustration of Neo-Classical realism theory’s application on the political field vis-à-vis Vietnamese Communist Leadership. My study relies on secondary source documents, composed of official governmental reports, scholars, experts and politicians’ papers, film documentaries, interviews of important personalities of the studied time period. The study demonstrated that P.R.C.’s foreign policy behaviour vis-à-vis a supposedly ally, the Vietnamese Communist, through a study period of two conflicts, is completely inconstant, although being consistent in the inconstancy. The results showed that there is no such logic of ‘bloc against another bloc’. Rather countries, in this case P.R.C., is simply fulfilling its own national interests, even if, in order to fulfill such national purpose, P.R.C. betrays and sells out a communist ally to turn in favour of the ‘enemy’, beginning with France, then moving on to the United-States.