"If you're ... pathetically weak, the country is going to be overrun with millions of people, and if you're strong, then you don't have any heart, that's a tough dilemma. ... I'd rather be strong."

So said President Donald Trump, on issuing his order halting the separation of children from parents caught breaking into the country. Trump's enemies are celebrating a victory. Yet the issue remains.

Under U.S. law, teenagers and tots cannot be detained for more than 20 days and must be held in the least-restrictive facilities. But if the children cannot be separated from the parents as they await trial, both will have to be released to keep families together.

We are back to "catch and release."

When that welcome news hits Central America, the migrant stream moving north will become a river that never ceases to flow.

The questions America and the West face might thus be framed:

Is there a liberal, progressive, Christian way to seal a 2,000-mile border, halt millions of migrants from crossing it illegally and send intruders back whence they came? Or does the preservation of Western nations and peoples require measures from which liberal societies today reflexively recoil?

Does the survival of the West as a civilization require a ruthlessness the West no longer possess?

Consider what our fathers did to build this country.

The English settlers brought in 600,000 slaves, ethnically cleansed the Indians, joined their cousins in a war to expel the French, then revolted and threw out those cousins to claim all the land to the Mississippi for ourselves.

Jefferson grabbed the vast Louisiana Territory for $15 million from Napoleon, who had no right to sell it. Andrew Jackson drove the Spanish out of Florida, sent the Cherokee packing on the Trail of Tears, and told a dissenting Chief Justice John Marshall where he could go.

Sam Houston tore Texas away from Mexico. "Jimmy" Polk took the Southwest and California in a war Ulysses Grant called "the most unjust ever fought." When the South declared independence, Lincoln sent a million-man army to march them back in a war that cost 600,000 lives.

William McKinley sent armies and warships to seize Puerto Rico, Hawaii, Guam and the Philippines. The indigenous peoples were not consulted. "God told me to take the Philippines," said McKinley.

The conquest and colonization of the New World and the creation of the United States and its rise to world power required acts of aggression and war of which many among our elites are ashamed. They exhibit their guilt by tearing down the statues of the men who perpetrated the "crimes" that created America. But of these elites, it may be fairly said: They could never have built a nation like ours.

Which brings us again to the larger questions.

While our forefathers would not have hesitated to do what was needed to secure our borders and expel intruders, it is not a settled matter as to whether this generation has the will to preserve the West.

Progressives may parade their moral superiority as they cheer the defeat of the "zero tolerance" policy. But they have no solution to the crisis. Indeed, many do not even see it as a crisis because they do not see themselves as belonging to a separate tribe, nation or people threatened by an epochal invasion from the Third World.

They see themselves as belonging to an ideological nation, a nation of ideas, whose mission is to go forth and preach and teach all peoples the gospel of democracy, diversity and equality.

And this is why the establishment was repudiated in 2016. It was perceived as too elite, too liberal, too weak to secure the borders and repel the invaders.

"If you're really, really pathetically weak, the country is going to be overrun with millions of people," said Trump Wednesday. Is he wrong?

Since the Cold War ended with the collapse of the Soviet Union, it has grown apparent that the existential threat to the West comes not from Czar Vladimir's Russian divisions returning to the Elbe.

The existential threat came from the south.

Half a century ago, Houari Boumedienne, the leader of a poor but militant Algeria, allegedly proclaimed at the United Nations:

"One day, millions of men will leave the Southern Hemisphere to go to the Northern Hemisphere. And they will not go there as friends. Because they will go there to conquer it. And they will conquer it with their sons. The wombs of our women will give us victory."

This is the existential crisis of the West.

Thus, Trump seeks to build a wall, turn back the intruders and bring Vladimir Putin back into the Western camp, where Russia belongs. Thus the new populist regime in Rome blocks boats of refugees from landing in Italy. Thus Angela Merkel looks like yesterday, and Viktor Orban like tomorrow.