National Review Online, December 8, 2015

Donald Trump has again succeeded in setting the terms of political debate, this time by calling for a temporary halt to the admission of all Muslims from abroad, whether as immigrants or as visitors ("nonimmigrants" being the technical term). Everyone's outraged, of course, but this is a topic that needs to be addressed head-on.

First of all, it's important to underline that Congress can exclude or admit any foreigner it wants, for any reason or no reason. Non-Americans have no constitutional right to travel to the United States and no constitutional due-process rights to challenge exclusion; as the Supreme Court has written multiple times, "Whatever the procedure authorized by Congress is, it is due process as far as an alien denied entry is concerned."

What's more, while the president doesn't have the authority that Obama has claimed, to let in anyone he wants for any reason (under the guise of "parole"), he does have the statutory authority to keep anyone out, for any reason he thinks best. From 8 USC §1182:

Whenever the President finds that the entry of any aliens or of any class of aliens into the United States would be detrimental to the interests of the United States, he may by proclamation, and for such period as he shall deem necessary, suspend the entry of all aliens or any class of aliens as immigrants or nonimmigrants, or impose on the entry of aliens any restrictions he may deem to be appropriate (emphasis added).

So in considering Trump's statement, the question is not whether it would be lawful but whether it would be good policy. (Barring the return of American citizens from abroad simply because they're Muslims is ridiculous and illegal, but it doesn't seem that Trump actually said that, despite the media's trumpeting of that point.) As usual, Trump is playing the part of your crotchety Uncle George holding forth on politics at the Thanksgiving dinner table. But the reason his careless and sloppy immigration commentary resonates is that no one else in public life is willing to address issues that worry — and, at this point, frighten — people. If "respectable" politicians refuse to even talk about the real problems caused by mass Muslim immigration, then a larger and larger share of the public will turn to carnival barkers unafraid of elite disapproval.

Under current trends, the United States will admit about 1 million new Muslim-origin immigrants over the next decade, plus hundreds of thousands of Muslim guest workers and foreign students. In addition, something like 50,000 young people from Muslim immigrant families turn 18 in the United States each year. Many of these individuals are productive citizens who pose no threat to our republic. Iman the supermodel, television's Dr. Oz, Fareed Zakaria, Coke CEO Muhtar Kent — whatever their merits or lack thereof, their Muslim origins pose no threat to us. Some are even politically conservative American patriots, such as our own Reihan Salam.

But large Muslim populations, continually refreshed by ongoing mass immigration, are a problem. Polling suggests between a quarter and a third are not attached to the principles of the Constitution, supporting things such as sharia law over U.S. law and the use of violence against those who insult Islam. Nor is this merely hypothetical; Muslims account for only about 1 percent of the U.S. population but account for about half of terrorist attacks since 9/11. That means Muslims in the United States are about 5,000 percent more likely to commit terrorist attacks than non-Muslims.

So what to do? A strictly religious test for immigrants or visitors, as Trump seems to suggest, while perfectly legal with regard to foreigners seeking entry, would obviously run against the grain of American political culture, and rightly so. Whether you believe that Mohammed flew to heaven on the back of his horse is no more anyone else's business than whether you believe in the virgin birth or the transmigration of souls.

But while Islam is indeed a religion, it is also more than that — and it is the political aspects that concern us. As Andy McCarthy noted last week, Islam's non-religious element — sharia — "involves the organization of the state, comprehensive regulation of economic and social life, rules of military engagement, and imposition of a draconian criminal code." That program of Islamic supremacism is fundamentally incompatible with the Constitution, and we should strive to minimize the number of people living in our country who hold such beliefs. As Walter Russell Mead wrote the other day, "a cosmopolitan and tolerant society can't thrive if it admits millions of migrants who hate and despise cosmopolitan values."

The narrowest solution would be to restore the principle of "ideological exclusion" to U.S. immigration law. With the end of the Cold War — which too many imagined to be the End of History — we eliminated the legal bar to enemies of America who were not actual members of terrorist organizations or card-carrying members of totalitarian political parties. Specifically, the law says the State Department is prohibited from keeping a foreigner out "because of the alien's past, current, or expected beliefs, statements, or associations, if such beliefs, statements, or associations would be lawful within the United States." In other words, since 1990 we have applied the First Amendment to all foreigners abroad seeking admission to our country. The only exception is if the secretary of state "personally determines that the alien's admission would compromise a compelling United States foreign policy interest" — note this exception is only for a "compelling . . . foreign policy interest," not a domestic-policy one, like limiting the number of residents who support killing apostates.

Even President Obama has paid (grudging) lip service to the ideological — as opposed to the violent — threat. In his Oval Office speech Sunday night he said "Muslim leaders here and around the globe have to ... speak out against not just acts of violence, but also those interpretations of Islam that are incompatible with the values of religious tolerance, mutual respect, and human dignity." So why aren't we keeping out people who adhere to such interpretations?

Such screening would be stricter for people coming as immigrants than for nonimmigrants (visitors). So long as he's not a terrorist, it doesn't matter too much to us if a Turkish businessman attending a trade show in Atlanta supports the killing of homosexuals. But for people who want to become permanent (or even long-term "temporary") residents, it does matter. At the very least, we should be asking things like whether they support freedom of religion and speech, regardless of content, even if it is insulting to other faiths. Of course people could, and would, lie, but the very fact that such a question is asked would send a message about what we expect of people hoping to live among us — that believing in Islamic supremacism is disqualifying even if you yourself do not use violence.

But large-scale immigration of non-violent Islamic supremacists also facilitates violence, by forming and sustaining neighborhoods that serve as cover and incubators for jihad attacks, however unintentionally. Muslim immigrant neighborhoods, and their mosques and other institutions, fit Mao's observation regarding the peasantry's role in China's war against the Japanese: "The people are like water and the army is like fish." DHS's chief intelligence officer told the House Select Committee on Intelligence in 2007, "As previous attacks indicate, overseas extremists do not operate in a vacuum and are often linked with criminal and smuggling networks — usually connected with resident populations [in the U.S.] from their countries of origin." (Emphasis added.)

The Somali community in Minneapolis is a prime example. Established through refugee resettlement, and continually expanded and refreshed by more resettlement (nearly 9,000 Somali refugees were admitted last year) as well as follow-on chain migration, it has been the source of dozens of recruits for Al Shabaab and ISIS, and dozens more supporters, even though most community members aren't necessarily terrorists or even fellow-travelers. Just this summer, a Somali graduate of a Minnesota high school died fighting for ISIS in Syria. As the Washington Times noted, immigration "is having the unintended consequence of creating an enclave of immigrants with high unemployment that is both stressing the state's safety net and creating a rich pool of potential recruiting targets for Islamist terror groups."

And many of those recruits are native-born, having grown up steeped in Islamic supremacism and alienated from the values of their native land. In Europe this has been the main threat; and here, the killers at Fort Hood and Chattanooga and Jihad Dad in San Bernardino were U.S.-born. It is often claimed that the United States is uniquely effective at assimilating the children of immigrants from the Islamic world. But these incidents suggest skepticism. While our Muslim population is indeed more prosperous, more dispersed, and more ethnically heterogeneous than Europe's, it seems likely that the main difference is simply that it's so much smaller. The EU has four or five times more Muslim residents than the United States; France and Germany each have at least 50 percent more Muslims than our country (roughly 4.5 million each versus 3 million here).

Even with our smaller Muslim population, we have trouble keeping track. The FBI is reported to have nearly 1,000 active probes into ISIS supporters in the United States. Of those, 48 suspects are under intensive, 24/7 surveillance, straining the agency's capacity. Senator Dan Coats, on the Select Committee on Intelligence, said just those 48 represented "a big resource drain. ... Almost overwhelming." If we continue current immigration policies, we can get rid of the "almost" — in France, due to the numbers, "The services are overwhelmed," according to one terrorism expert.

There's really no way around it: Continuing to admit 1 million Muslim immigrants per decade will translate into more attacks. We need to cut Muslim immigration. But limiting the cuts to Muslim-majority countries would exclude Christians and other non-Muslims and also ignore Muslim immigration from non-Muslim countries such as India, Russia, France, and England.

So alongside ideological screening we need to cut immigration overall, focusing on the categories most likely to cause problems. That means eliminating the visa lottery, an absurd program in its own right but also the source of a disproportionate share of Muslim immigration; limiting family immigration to the closest relations, to prevent a cascading chain of relatives; dramatically curbing refugee resettlement, allowing us to help many more people while keeping the potential security threats off shore; and reducing the number of foreign-student admissions, the feeder program for a large share of new permanent immigration from the Islamic world.

None of these measures is a magic solution. Efforts to screen out Islamic supremacists will often fail. Limiting family migration to spouses would still permit the immigration of people like San Bernardino jihadist Tashfeen Malik. Full assimilation of existing Muslim communities, even if new inflows were reduced to a trickle, would still take time, if it's possible at all.

But if we just keep doing what we're doing now, we can't expect a different result. Trump's sweeping call to stop all Muslim travel to the U.S. will resonate with people rightly frustrated with our rulers' insouciant approach to the threat we face. Rather than simply point in outrage at Trump's crude prescription, responsible policymakers should offer a grown-up alternative.