Every nation has a natural right and responsibility to determine who is admitted to its borders. This is what defines a country and ultimately determines whether its culture, values, and institutions will endure.

The unique qualities that develop within each country’s borders naturally make some more desirable places to live than others. These differences drive immigration patterns. The more successful a nation, the greater the demand to immigrate to it.

Most of the world’s 7.5 billion people live in violent and impoverished countries. It is no wonder that so many find the United States an attractive alternative. Yet uncontrolled and indiscriminate immigration from any and all of them risks importing the same undesirable conditions here, and destroying the qualities that encouraged immigration in the first place.

History offers many examples of great civilizations that have succumbed to this paradox, and the current crisis on our southern border poses a fundamental test of whether ours may soon join them.

America has traditionally welcomed the truly persecuted who have escaped to our shores, but what is unfolding today makes a mockery of our asylum laws. The much-publicized crowd at the border is not a peaceful caravan of asylum seekers, as many have attempted to portray it. A “caravan” is a group of people traveling legally and peacefully through a foreign land. An “invasion” is a group of people attempting to violate a nation’s border by force, whether by military or mob action.

The vast majority of those camped on our southern border are military-aged males. Authorities have already identified roughly 600 as known criminals, and Mexican law enforcement has reportedly arrested roughly a hundred for crimes committed there. The fact that this force has attacked both Mexican and U.S. law enforcement, with several injuries reported, contradicts any claims that as a group they come with peaceful intent.

Nor are they “asylum seekers” in any conventional sense. No doubt, many are nonviolent and simply caught up in the group dynamic of a mob. But poverty and violence in one's home country does not entitle one to enter ours under an asylum claim. Asylum is reserved for those who have been specifically targeted for harm by their own government based on their race, religion, nationality, political opinion, or particular social group, and who have entered directly into this country from their own.

In those instances, asylum is reached by crossing a border into the next safe country and thus achieving separation from that government. A Central American arriving in Mexico has already achieved this and therefore has no claim to asylum in any other country. The appropriate request is to the government in Mexico — a request that some from the original migrant caravan have already made.

Nothing succeeds like success. If this throng is allowed to muscle its way into the United States, we can expect many and larger groups to follow.

If anything, the crisis should emphasize the importance of completing the border wall that Congress first authorized in 1996, and which President Trump is desperately trying to complete. A forceful incursion over our border can only be repelled by the application of equal or greater force, and that's a recipe for violence or even bloodshed. The physical separation provided by a wall can prevent that, protecting the officers who place their lives on the line in defense of our laws. It also protects the law-breakers themselves from the violent conflict their behavior would otherwise make inevitable.

Orderly immigration, regulated by law and protected by secure borders, is a prerequisite to a prosperous nation. If our immigration laws are not enforced then our borders become meaningless, and America becomes nothing more than a vast open territory between Canada and Mexico, susceptible to every social, political, and economic disorder brought to it. This seems to be the ultimate aim of the American Left and its powerful chorus in the media. We are fortunate in this crisis to have a president obedient to his constitutional command to “take care that the laws be faithfully executed.”

Tom McClintock represents California's 4th Congressional District.