“Can borders be controlled? Yes, each country has a right to control its borders, who enters and who leaves, and countries that are in danger — of terrorism or the like — have more right to control them more.” --Pope Francis

The inextricable relationship between borders and national identity, culture, and sovereignty was for so long understood that few popes ever spoke on the relationship between borders and immigration before the World Wars. St. Thomas Aquinas wrote on borders and immigration in his 13th century masterwork the Summa Theologica. Relying on analysis of Sacred Scripture, Aquinas explained that while nations are called to exercise charity to foreigners, each nation’s chief responsibility is to its own people, with the dual aims of preserving national unity and the common good.

A nation’s relations with foreigners, Aquinas explained, may be: “twofold: peaceful, and hostile: and in directing both kinds of relation the Law contained suitable precepts.” That is to say, God’s Law demands nations respond differently to peaceful and hostile foreigners. Aquinas declared that a nation has the right to reject or repel immigrants it deems “hostile.” Furthermore, in order for immigrants to be adopted into a country, they must first adopt that country’s culture and way of life, stating: “The reason for this was that if foreigners were allowed to meddle with the affairs of a nation as soon as they settled down in its midst, many dangers might occur, since the foreigners not yet having the common good firmly at heart might attempt something hurtful to the people.”

Centuries later, especially in the wake of World War II, immigration escalated exponentially, prompting Catholic leaders to speak on the subject in order to inform the consciences of the faithful. Pope Pius XII was one of the 1st pontiffs to directly and clearly address the issue of immigration, laying particular emphasis on not only the common good of a nation but the common good of the whole human race. Witnessing countless masses of refugees displaced by the near-global conflict, Pius XII asked Americans: “Is the policy concerning immigration as liberal as the natural resources of a country so abundantly blessed by the Creator would allow and as the needs of other countries seem to require?” In his 1952 Apostolic Exhortation Exsul Familia Nazarethana, Pius XII wrote: "Since land everywhere offers the possibility of supporting a large number of people, the sovereignty of the State, although it must be respected, cannot be exaggerated to the point that access to this land is, for inadequate or unjustified reasons, denied to needy and decent people from other nations, provided of course, that the public wealth, considered very carefully, does not forbid this.

The pontiff was speaking of immigration of necessity — not of want, not of whim, but of necessity — the sort of immigration Aquinas would classify as “peaceful.” Families displaced by war and violence still seek shelter in nations blessed by God with abundant riches, and while every nation has a duty to its own people, it has also a duty to mankind as a whole.

But today hundreds of thousands of fighting-age males are not necessarily fleeing war — and if they were, they would leaving behind their women and children while they refuse to fight. Asylum claims are a scam, are too readily accepted by the derelict our government. Even fleeing economic impoverishment is not asylum nor always necessary: America’s success is not predicated simply on its geography and topography, but on the will, imagination, and fiery spirit of its people; if America can produce a culture of success and prosperity, so also can other nations, if they are not readily abandoned by their own people.

Pope Benedict XVI spoke of this principle in his 2013 Message for the World Day of Migrants and Refugees, saying: “[E]ven before the right to migrate, there is need to reaffirm the right not to emigrate, that is, to remain in one’s homeland.” That is to say, a right to emigrate, to leave one’s own country and attempt to enter another’s, may be mitigated or nullified if one does not avail oneself of the right to simply remain in one’s own country.

There is the further problem of what Aquinas would classify as “hostile” immigrants. America’s southern border is being flooded with gang members and cartel agents, drug-smugglers carrying inordinately lethal doses of fentanyl, potential and even confirmed terrorists from across the Atlantic. And yet the biden regiem’s obscenely lax policies and practical weaponization of “parole” procedures have admitted millions of illegal immigrants into the nation — nearly three-quarters of a million through “parole” procedures in 2023 alone!

Then there is the very nature of illegal immigration. Aquinas stressed the importance of respect for a nation’s laws and assimilation for its culture. So also did Pope Pius XII when he said that an immigrant: “must be conscious of what he owes the people that welcomes him and tries to facilitate his progressive adaptation to his new way of life.” By the very mode of entry sought by illegal immigrants, they are flouting and violating the very 1st set of American laws they encounter. How can they be expected to respect the remainder of the nation’s laws or assimilate to the American way of life (which is being rapidly eroded by the immigration crisis) if they will not even attempt to enter the nation legally?

In order to prevent the undermining and eventual destruction of a nation’s laws, culture, and way of life, stringent immigration regulation is necessary. Recognizing this as both a reality and a good, the Catechism of the Catholic Church teaches: "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."

There are, of course, other factors to consider with immigration, such as the natural resources and economic state of the country receiving immigrants — the Catechism again explains: “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.” This is why Pope St. John Paul II stated, in his 2001 Message for the World Day of Peace" “The challenge is to combine the welcome due to every human being, especially when in need, with a reckoning of what is necessary for both the local inhabitants and the new arrivals to live a dignified and peaceful life.”

The regulation of one’s borders, then, is most certainly a principle not only permitted but advocated by the Catholic Church, going back centuries and centuries. Although the circumstances of the modern world have changed what immigration looks like and even how it’s discussed, Catholic teaching addresses the unchanging moral dimension of the issue.