This article was originally posted at Providence.

The Paris terror attack by the Islamic State in Iraq and the Levant (ISIL) has transformed the immigration debate in this country: whether to allow at least 10,000 Syrian refugees into the United States over the next year, as proposed by President Obama. Fearing that terrorists will slip in among the refugees, many conservatives and GOP lawmakers are calling for a halt to any such plan.

Earlier this week during the Asia-Pacific Economic Cooperation (APEC) summit, Mr. Obama lashed out at those proposing that only Christian refugees be allowed into the country.

“ISIL seeks to exploit the idea that there’s war between Islam and the west, and when you see individuals in positions of responsibility suggesting Christians are more worthy of protection than Muslims are in a war-torn land, that feeds the ISIL narrative,” he said. “I cannot think of a more potent recruitment tool for ISIL than some of the rhetoric coming out of here in the course of this debate.”

A Christian approach to the human catastrophe of the Syrian refugee crisis—partially instigated and immeasurably worsened by Mr. Obama’s floundering foreign policy—must reject legislation rooted in fear, bigotry, and nativism. We need a mature debate about how to respond with prudence and compassion to this crisis.

Yet we also have an obligation to expose the intellectually and morally bankrupt arguments that cascade unceasingly from the mouth of this president.

The Islamic fascists who fill the ranks of ISIL already have a narrative of war between themselves and the West. Its latest expression can be found in the ISIL statement last weekend claiming responsibility for the Paris attacks. Here is an excerpt:

Let France and all nations following its path know that they will continue to be at the top of the target list for the Islamic State and that the scent of death will not leave their nostrils as long as they partake in the crusader campaign, as long as they dare to curse our Prophet (blessings and peace be upon him), and as long as they boast about their war against Islam in France and their strikes against Muslims in the lands of the Caliphate with their jets, which were of no avail to them in the filthy streets and alleys of Paris. Indeed, this is just the beginning.

Here is their narrative: a vision of the world under their totalitarian boot, ruled by theocrats guided by medieval interpretations of the Quran. The Muslim refugees fleeing this dystopian horror are the enemies of ISIL as surely as the Western infidels, considered worthy only of execution.

President Obama, even at this late hour, refuses to confront the significance of this threat to civilization. He fails to understand the Will to Power that feeds its heart of darkness, and how it gains strength from Western weakness.

“I cannot think of a more potent recruitment tool for ISIL than some of the rhetoric coming out of here in the course of this debate.”

Only a mind confused by utopian delusions could fail to see that the most potent recruitment tool for radical evil is its survival and success on the battlefield—in the face of Mr. Obama’s feckless “international coalition” to stop it. This helps explain why tens of thousands of Muslim men—from the Middle East, Africa, Europe, and the United States—have left everything to join its unholy cause.

The fact is that ISIL retains control of strategic cities and resources in Syria and Iraq. They have expanded globally, gaining safe havens and cells in Afghanistan, Yemen, Libya, and North Africa. They launched suicide attacks in Beirut that killed dozens and injured hundreds. They took down a Russian commercial airliner, killing all 224 people on board. And they unleashed on the citizens of Paris the most devastating assault since the Second World War.

Here is their most potent recruitment tool: Western impotence, a lack of civilizational confidence, and a deficit of military resolve—even as the barbarians are at the gate. “We have contained them,” President Obama claimed, just hours before the Paris attacks. Mr. Obama’s conceptual conceits have contributed mightily to this state of affairs. “Nonsense in the intellect,” wrote C.S. Lewis, “draws evil after it.”

The Obama Doctrine has been cast adrift by its intellectual nonsense, and a cataract of evil has arrived in its wake.

Joseph Loconte is an associate professor of history at the King’s College in New York City and the author of A Hobbit, a Wardrobe, and a Great War: How J.R.R. Tolkien and C.S. Lewis Rediscovered Faith, Friendship, and Heroism in the Cataclysm of 1914-1918.