Catechism of the Catholic Church §2316 — excerpt
The production and the sale of arms affect the common good of nations and of the international community. Hence public authorities have the right and duty to regulate them.
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.