Immigration and a Nation's Duty to Defend Itself from Invasion (by Steve C. Halbrook)

Just as an individual has a right to self-defense (Exodus 22:2, 3), so does a nation. And if nations should oppose invading soldiers, then they should likewise oppose invading criminals. The goal is the same: to protect citizens. It is inconsistent to accept the former and reject the latter, for there is no practical difference between a pillaging army of soldiers and a pillaging army of criminals—which some illegal immigrants happen to be.

An unsecured border means subjecting citizens to violent criminals who cross it. This violates the command to "Rescue those who are being taken away to death" (Proverbs 24:11a). According to one article, "Border States Deal With More Illegal Immigrant Crime Than Most, Data Suggest." But this should be self-evident, with or without data; criminals will naturally cross borders to both escape the law in their own countries—and to find fresh opportunities to commit crimes in the country that they enter. 

Moreover, an influx of immigrants with no respect for a nation’s laws can easily lead to war itself. Consider our own situation: we have some illegal immigrants who not only disrespect our laws and our borders, but also support a "reconquista" of the southwest. 

But whether there is a civil war or not, we already have a problem with violent crime due to illegal immigration, and our civil rulers therefore have a duty to protect their citizens via secure borders and a careful legalization process.

From Border Meltdown: Biblical Principles to Address our Immigration Crisis by Steve C. Halbrook