163 Hence among the very serious obligations incumbent upon men of high principles, We must include the task of establishing new relationships in human society, under the mastery and guidance of truth, justice, charity and freedom—relations between individual citizens, between citizens and their respective States, between States, and finally between individuals, families, intermediate associations and States on the one hand, and the world community on the other. There is surely no one who will not consider this a most exalted task, for it is one which is able to bring about true peace in accordance with divinely established order.
Source: Pacem in Terris (Vatican.va)