It is important to note therefore that a world which is divided into blocs, sustained by rigid ideologies, and in which instead of interdependence and solidarity different forms of imperialism hold sway, can only be a world subject to structures of sin. The sum total of the negative factors working against a true awareness of the universal common good, and the need to further it, gives the impression of creating, in persons and institutions, an obstacle which is difficult to overcome.(Papal Encyclical, Sollicitudo Rei Socialis, 30 December 1987)
It was inevitable that by developing antagonistic systems and centers of power, each with its own forms of propaganda and indoctrination, the ideological opposition should evolve into a growing military opposition and give rise to two blocs of armed forces, each suspicious and fearful of the other's domination. International relations, in turn, could not fail to feel the effects of this "logic of blocs" and of the respective "spheres of influence." The tension between the two blocs which began at the end of the Second World War has dominated the whole of the subsequent forty years. Sometimes it has taken the form of "cold war," sometimes of "wars by proxy," through the manipulation of local conflicts, and sometimes it has kept people's minds in suspense and anguish by the threat of an open and total war. Although at the present time this danger seems to have receded, yet without completely disappearing, and even though an initial agreement has been reached on the destruction of one type of nuclear weapon, the existence and opposition of the blocs continue to be a real and worrying fact which still colors the world picture.
This happens with particularly negative effects in the international relations which concern the developing countries. For as we know the tension between East and West is not in itself an opposition between two different levels of development but rather between two concepts of the development of individuals and peoples both concepts being imperfect and in need of radical correction. This opposition is transferred to the developing countries themselves, and thus helps to widen the gap already existing on the economic level between North and South and which results from the distance between the two worlds: the more developed one and the less developed one. (Papal Encyclical, Sollicitudo Rei Socialis, 30 December 1987).