Pope Paul VI
Populorum Progressio §77
Populorum Progressio: On the Development of Peoples
77 Nations are the architects of their own development, and they must bear the burden of this work; but they cannot accomplish it if they live in isolation from others. Regional mutual aid agreements among the poorer nations, broader based programs of support for these nations, major alliances between nations to coordinate these activities—these are the road signs that point the way to national development and world peace.
Source: Populorum Progressio (Vatican.va)