G.K. Chesterton wrote that “the modern world is full of the old Christian virtues gone mad. The virtues have gone mad because they have been isolated from each other and are wandering alone.”

His observation seems applicable to the current debate about taking in Syrian refugees. The “modern world” in this case is made up of the European elites, the Obama administration and Christian clerics who follow their lead. The virtue gone mad is compassion.

What Chesterton probably had in mind when he wrote about “mad” virtues was Aristotle’s doctrine of the mean (which was later adopted by Aquinas). According to Aristotle, the virtuous course of action is always situated between two extremes or vices. For example, the virtue of courage is a mean between cowardice on the one hand and foolhardiness on the other. In the case of compassion, it would seem that the two extremes to avoid are callousness on the one side and imprudence on the other.

Chesterton noted that when the virtues become unmoored from each other, they can do “terrible damage.” The Obama administration and other advocates for the refugees are not being criticized for their compassion, but because they are being dangerously imprudent. The fear is that their imprudence will result in damaging consequences.

The damaging consequences of imprudent immigration policies can already be seen in Europe. Parallel societies consisting of Muslim immigrants and their children and grandchildren have grown up all over Europe. These enclaves, in turn, have become launching pads for deadly attacks: the Paris massacre, the London Tube bombing, which resulted in 756 casualties, and the Madrid training bombings, which left 2,200 casualties. These, of course, are only the more spectacular incidents. Lower levels of violence — beatings, stabbings and rapes — are an everyday occurrence.

For example, in England and Sweden, rapes committed by Muslim immigrants have reached epidemic proportion, with 1,400 rapes in one small English city alone. The eventual reaction to mass immigration is likely to be just as violent. Lately, there has been much talk of civil war in Europe.

The mass importation of Muslim immigrants was sold to the Europeans in the name of compassion and as retribution for the past sin of anti-Semitism. Those very few who publicly objected were denounced as “xenophobes,” “racists” and, of course, “Nazis.”

In a similar vein, the Obama administration has cast the debate over Syrian refugees in moral terms. President Obama himself has castigated the opposition as “shameful” and “contrary to American values.” At a press conference in Manila, Obama mocked the opposition as being “scared of widows and orphans,” and he added, “We don’t make good decisions if [they are] based on hysteria and an exaggeration of risks.”

“Hysteria and an exaggeration of risks”? Ironically, Obama was speaking in the Philippines — a place where almost every store and shop is protected by heavily armed security guards due to a decades-old Muslim insurgency in that country. Philippine troops have been engaged in a long guerilla war with the insurgents, and, even though Muslims on Mindanao (the second-largest island in the Philippines) have been granted their own autonomous region, the Philippines continues to be racked by bombings and kidnappings.

In 2013, 60,000 Christians were forced to flee a city in the southern Philippines to escape an attack by Muslim terrorists. As a prime example of what can happen when the Muslim population passes a critical point, the Philippines was hardly the place to laugh about exaggerated risks.

Critics of the Syrian refugee program argue that the risk of admitting 10,000 or more refugees creates a disproportionately large danger. If they’re right, then the advocates for admission may be acting rashly. The former seem to have a strong case. The Islamic State (ISIS) has made no secret of its intention to infiltrate refugee groups. Moreover, several U.S. intelligence experts and officials have admitted that there is no effective vetting system. Jeh Johnson, the head of Homeland Security, has said that “we’re not going to know a whole lot” about Syrian refugees. FBI Director James Comey told Congress that the FBI cannot adequately check the backgrounds of Syrian refugees because the necessary records do not exist. Former FBI director James Kallstrom said the refugee policy was “crazy.” 

Michael McCaul, the chairman of the House Homeland Security Committee, stated that “we do not have the intelligence needed to vet individuals from the conflict zone.” Assistant director of the FBI’s Counterterrorism Division, Michael Steinbach, said of the vetting process that “it’s not even close to being under control.” Director of National Intelligence James Clapper, CIA Director John Brennan and NCTC Director Nicholas Rasmussen have made similar statements.

Now couple those assessments with the fact that it only takes a few jihadists to inflict massive casualties. Two men with AK-47s can kill hundreds. The bomb that killed 224 passengers on a Russian airliner was probably placed on board by a single individual. Of course, ISIS and other terrorist groups have set their sights much higher than that. They are hoping to soon acquire biological weapons and nuclear devices that will allow them to kill thousands, if not tens of thousands.

The vast majority of refugees probably have no such intentions. But it would be a mistake to project Western and Christian values onto them. The reason it’s so difficult for Muslim immigrants to assimilate to Western culture is because Islamic culture is in many ways antithetical to the West. After the Paris attacks, only 30 Muslims showed up for an anti-jihad rally. When a moment of silence was called for victims of the Paris massacre at a soccer match in Greece, Turkish soccer fans booed and chanted, “Allahu akbar” (God is great).

Meanwhile, in European refugee camps, Christian refugees have had to be taken to separate facilities because of repeated attacks on them by Muslim refugees. Individual Muslim refugees may be good and peaceful people, but it should be kept in mind that they are, nevertheless, the bearers of their culture — a culture that inclines toward intolerance and supremacism.

As Chesterton noted, when the virtues get out of hand, they can be destructive. This certainly seems to be the case in Europe, where the compassionate response to migrants and refugees has arguably resulted in far more harm than good. Whether this will be the case in the United States, with its much smaller population of Muslims, remains to be seen. However, in view of the risks and in view of the warnings by intelligence officials about the gaps in the vetting process, the prudent thing would be to call a halt, or at least a pause, to the Syrian refugee resettlement.

One of the voices for admitting the Syrian refugees is the U.S. Conference of Catholic Bishops. In fact, earlier in the year, the USCCB called for the U.S. to take in 100,000 Syrian refugees. With the help of Catholic Charities, the USCCB resettled 27% of all refugees in the U.S. in 2014, so it’s understandable that the bishops would be deeply concerned about the fate of the Syrians. However, their assessment of the current situation seems to rely heavily on assurances from the Obama administration that everyone will be properly vetted. Consider these recent statements:

— Archbishop Joseph Kurtz, president of the USCCB: “The vetting of newcomers will have been completed by government agencies long before Church agencies become involved.”

— The Archdiocese of New Orleans: “Anyone resettled through our program is referred from the U.S. State Department after extensive security checks and background screenings. … We will prayerfully await direction and guidance from the State Department, Homeland Security and others …”

— Patrick Winn, head of Catholic Charities for the Diocese of Rockford, Ill.: “There still stays in place the strong vetting process under the State Department, Homeland Security and the United Nations.”

Meanwhile, the FBI has revealed that it is pursuing 900 investigations against Islamic State-inspired operatives in the U.S. In response to critics of mass immigration, the bishops have been in the habit of warning against “irrational fears.” But in light of the extensive FBI investigations, it seems that some of these fears may be quite rational. And over in Europe, fears that at one time were labeled “irrational” have turned out to be well-founded.

According to Prime Minister Manuel Valls, French police have conducted at least 600 raids targeting Islamic extremists since the Nov. 13 Paris attacks. Assuming that the police only have the resources to go after the most likely suspects, this suggests that there is already a critical mass of terrorists and terrorist sympathizers in France.

In the debate over the Syrian refugees, those who urge compassion should take care that their compassion is balanced by prudence. If European leaders had exercised more prudence in the past, an event such as the Paris massacre might have remained nothing more than the irrational imagining of an excitable few. Instead, it represents the nightmare possibilities with which all Europeans must now live.

William Kilpatrick is the author of  Christianity, Islam and Atheism: The Struggle for the Soul of the West.