129 Nevertheless, We are hopeful that, by establishing contact with one another and by a policy of negotiation, nations will come to a better recognition of the natural ties that bind them together as men. We are hopeful, too, that they will come to a fairer realization of one of the cardinal duties deriving from our common nature: namely, that love, not fear, must dominate the relationships between individuals and between nations. It is principally characteristic of love that it draws men together in all sorts of ways, sincerely united in the bonds of mind and matter; and this is a union from which countless blessings can flow.
Source: Pacem in Terris (Vatican.va)