NRO's Derbyshire wants to deny Muslims entry to the U.S. and "expel foreign Muslim residents"

In a September 20 column headlined "Islamophobophobia," National Review Online columnist John Derbyshire explained why he takes issue with the concept of Islamophobia, which he previously discussed in a review of Robert Spencer's Religion of Peace? Why Christianity Is and Islam Isn't (Regnery, 2007). In the column, Derbyshire wrote that it would be wise to "deny entry to foreign Muslims" and "to expel ... resident foreign Muslims":

It's odd that I don't like Islamophobia because I would answer a prompt yes to all the following questions

• As religions go, and taking historical and geographical variations into account, has Islam been, on average, the most intolerant and obscurantist of the big world faiths?
• Whatever may have been the case in the past, and however things may develop in the future, is it true that Islam today is bringing forth an exceptionally large crop of homicidal fanatics willing to perform deeds of staggering cruelty, inhumanity, and stupidity in the name of their religion?
• Would it be wise of Western countries, in the present state of affairs, to "fence off" Islam -- that is, to deny entry to foreign Muslims, to expel -- regretfully, politely, and humanely, but firmly -- resident foreign Muslims, and to restrict the activities of Muslim citizens (preventing them, for example, from proselytizing in our jails, or working in defense establishments)?
• Has Islamic civilization, wherever it has settled, been, by comparison with Western civilization, culturally very arid? (Thanks to Bill Buckley, in a private conversation on this topic, for the mot juste there.)

Derbyshire continued:

As to my third bullet point -- I'm working through them -- it is surely clear now that our troubles with immigrant Muslims are a mere aspect of our larger troubles with the great floods of Third World immigrants we have allowed to come into our countries this past forty years. This was a horrible and insane blunder, as wise men pointed out very early in the process. "Diversity" is a bust.

[...]

Would I exclude foreign Muslims from settlement in the U.S.A.? Yes, I would; but this is not actually saying much, as I would stop all mass immigration if I could. Islam needs particular attention because of the sheer quantity of lunacy it has thrown up in the present generation; but it is not the only counterexample to the Diversity Theorem, only the most pressing one.

Finally, in a footnote to his article, Derbyshire explains why he dislikes the word "Islamophobia," stating that while phobias are irrational, "fear of Islam is perfectly rational":

Roger Kimball tells me this is the wrong word. A phobia (says Roger) is an irrational fear of something. Fear of Islam is perfectly rational! I leave you to discuss this among yourselves.