Now that French rioting has entered into its tenth day, this essay by Fukuyama is worth a read:

We have tended to see jihadist terrorism as something produced in dysfunctional parts of the world, such as Afghanistan, Pakistan or the Middle East, and exported to Western countries....There is good reason for thinking, however, that a critical source of contemporary radical Islamism lies not in the Middle East, but in Western Europe. In addition to Bouyeri [Van Gogh's murderer] and the London bombers, the March 11 Madrid bombers and ringleaders of the September 11 attacks such as Mohamed Atta were radicalized in Europe....

We profoundly misunderstand contemporary Islamist ideology when we see it as an assertion of traditional Muslim values or culture. In a traditional Muslim country, your religious identity is not a matter of choice; you receive it, along with your social status, customs and habits, even your future marriage partner, from your social environment. In such a society there is no confusion as to who you are, since your identity is given to you and sanctioned by all of the society's institutions, from the family to the mosque to the state.

The same is not true for a Muslim who lives as an immigrant in a suburb of Amsterdam or Paris. All of a sudden, your identity is up for grabs; you have seemingly infinite choices in deciding how far you want to try to integrate into the surrounding, non-Muslim society. In his book "Globalized Islam" (2004), the French scholar Olivier Roy argues persuasively that contemporary radicalism is precisely the product of the "deterritorialization" of Islam, which strips Muslim identity of all of the social supports it receives in a traditional Muslim society.

The identity problem is particularly severe for second- and third-generation children of immigrants. They grow up outside the traditional culture of their parents, but unlike most newcomers to the United States, few feel truly accepted by the surrounding society....

Integration is further inhibited by the fact that rigid European labor laws have made low-skill jobs hard to find for recent immigrants or their children. A significant proportion of immigrants are on welfare, meaning that they do not have the dignity of contributing through their labor to the surrounding society. They and their children understand themselves as outsiders.

It is in this context that someone like Osama bin Laden appears, offering young converts a universalistic, pure version of Islam that has been stripped of its local saints, customs and traditions. Radical Islamism tells them exactly who they are--respected members of a global Muslim umma to which they can belong despite their lives in lands of unbelief. Religion is no longer supported, as in a true Muslim society, through conformity to a host of external social customs and observances; rather it is more a question of inward belief.

This account is, I think, incomplete: Bin Laden is popular in the middle east as well, in addition to western Europe. Nevertheless, the point remains: a large number of terrorist acts is perpertrated by Muslim immigrants to the West.

Nor is this only a question of terrorism:

Sarkozy says that violence in French suburbs is a daily fact of life. Since the start of the year, 9,000 police cars have been stoned and, each night, 20 to 40 cars are torched.”

I'm naturally inclined towards a liberal immigration policy, but these facts suggest otherwise. Every time an immigrant from Saudi Arabia or north Africa is admitted, there is a small chance he will turn out to be a suicide bomber. This is not true for immigrants from China or Hindu immigrants from India. It is madness not to include this fact in the cost-benefit calculations associated with immigration. The right question to ask is: what is the expected number of 9/11's that we are willing to accept for the sake of a liberal immigration policy? Would we accept such an immigration policy if it meant that a 9/11 every year was probable? Every decade? Every few decades?

My answer is that the expected number of terrorist acts deriving from an immigration policy ought to be zero, or pretty damn close to zero. However, the solution is not to cut off immigration, but rather, be more selective in the type of immigrants admitted. In particular, I think immigration from countries with a high likelihood of terrorism should be about zero. The drop in immigration can be made up for by accepting more immigrants from other countries, e.g. China and so on.