Catechism of the Catholic Church §2439 — excerpt
Rich nations have a grave moral responsibility toward those which are unable to ensure the means of their development by themselves or have been prevented from doing so by tragic historical events.
This translation is under copyright, so only the cited words are quoted here. Follow the link for the full text. Translation: English translation of the Catechism of the Catholic Church, 2nd ed. (Libreria Editrice Vaticana), as posted at vatican.va.