As the father of a family has not only the right but also the duty to protect those in his charge, the properly constituted authorities of a state have a duty to use their power to advance the common good of the nation. Should prudential considerations—such as the danger “of terrorism or the like”—suggest that restrictions on immigration are in the common good, those authorities have not only the right but also the duty to impose such restrictions.More HERE. Share
As the Catechism of the Catholic Church notes:
Political authorities, for the sake of the common good for which they are responsible, may make the exercise of the right to immigrate subject to various juridical conditions, especially with regard to the immigrants' duties toward their country of adoption. Immigrants are obliged to respect with gratitude the material and spiritual heritage of the country that receives them, to obey its laws, and to assist in carrying civic burdens (CCC 2241).If we follow the logic of Pope Francis's words (which echo not only those of the Catechism but those of his two immediate predecessors in their annual messages for the World Day of Migrants and Refugees, as well as in their other writings on the topic), those who would deny that a country has the right to control its borders are denying that the country has a right to exist. Because a country without some control over its borders has, essentially, no borders at all.
All of this seems so obvious, not only from natural law but from common sense, that one may wonder why anyone would assume that the Church favors unrestricted immigration. Part of the answer lies in the emphasis that is often placed on a separate but related aspect of Church teaching: namely, the personal right of migration that flows from the inherent dignity of the human person. But while the right of migration speaks to the need to allow someone in straitened circumstances to leave his country of origin (and to bring with him those under his care, his family above all), it does not entail an unlimited right to settle wherever he may wish.
As the Catechism notes (again in para. 2241): "The more prosperous nations are obliged, to the extent they are able, to welcome the foreigner in search of the security and the means of livelihood which he cannot find in his country of origin" (emphasis added). (Read more.)