Eugene Volokh writes,

If you think you can prove someone is a terrorist, lock him up. If you have probable cause to think he’s a terrorist, and think you can develop proof beyond a reasonable doubt, arrest him. Even if you have only suspicion, follow him, ask people about him, and so on. But if you don’t have enough to prosecute or even arrest someone, you can’t take away his constitutional rights, even if you suspect he’s a terrorist (or if you suspect he’s a drug dealer or a gang member or whatever else).

He is talking about President Obama’s proposal to deny guns to people on the “no-fly” list.

In general, I think that the “no-fly” list and the “terrorism watch list” are of doubtful value. The latter, according to Wikipedia, has one million names. I do not believe that any agency is watching one million people. And, of course, the San Bernadino shooters were on neither list, as far as I know.

It is, once again, time to re-read David Brin’s The Transparent Society. You may also wish to read or re-read my essay on it.

Brin’s vision bothers many people. However, I think it is the most reasonable equilibrium in a world of terrorism and powerful surveillance technology.

In my post on Libertarians and Mass Shootings, I wrote,

As of this morning, that still would be my guess. A Charles Manson who happens to be Arab-American.

Of course, I have plenty of opportunity to be wrong.

Just to be clear, I was wrong. What made me doubt that Islamic radicalism was a factor was the place where the couple committed terrorism. I am still puzzled that they chose a low-value target. I find myself wondering that perhaps their real goal was to kill police with the bomb that they reportedly left at the scene (which either did not explode or was not a bomb), and the initial murders were a way of getting the police to come en masse. But in any case, the facts as they have emerged do not make a good case for gun control as a solution.

The Washington Post writes,

Most [of the Paris terrorists] had already been flagged as potential security threats. But so had tens of thousands of others — 20,000 in France alone — and the plotters were careful not to stand out or give law enforcement an excuse to arrest them.

I have said before that when a terrorist watchlist gets large enough, it becomes like an odometer that rolls back to zero. If you’re “watching” 20,000 people, you are not really watching anyone. And I think that it is reasonable to suppose that adding Syrian refugees will eventually add to the number of people on a watch list.

One argument that I have seen for allowing Syrian refugees runs as follows: it is easier to enter this country as a tourist than a refugee, therefore allowing refugees does not really add to the threat of terrorism. If you have made such an argument, do you really believe it? Think through your other implicit beliefs.

1. There must not be much point in vetting Syrian refugees to any greater extent than we vet tourists. In that case, “vetting” is pretty much an empty theatrical gesture.

2. There may not be much point in having a Department of Homeland Security. After all, if terrorist attacks are not really preventable, then why are we spending billions of dollars supposedly trying to prevent them?

3. Addimg Syrian refugees does not add to the risk of an intelligence failure, due to resources being diverted to screen refugees or to the refugee population making it easier for terrorists to blend in. This is because (a) there is no such thing as an intelligence failure. Or (b) dealing with Syrian refugees imposes zero marginal costs of intelligence resources.

It may be perfectly legitimate to believe these things, although I do not myself believe them. But if there is a way to believe that adding Syrian refugees adds no risk without believing such things, then I cannot see it.

I think a more reasonable statement in defense of taking in refugees would be that although it adds to the risk of a terrorist attack, the additional risk is small relative to the benefits of allowing refugees.

Alex Tabarrok writes,

Even 4-year-old Syrian orphans are too dangerous to welcome to the United States, says New Jersey Gov. Chris Christie. What sort of man turns away desperate orphans out of fear?

Four-year-old orphans aside, it is not unreasonable to be concerned about the security challenges posed by Syrian refugees. It requires more than just screening out known radicals, a task which is difficult enough. Ideally, you would want to screen out those who may become disenchanted and radicalized over here, and that is impossible to predict. It does not take many Type I errors to have catastrophic results.

I think that there is rhetorical excess on both sides of the issue. A long time ago, I said that there is a lot of writing that is not designed so much to change anyone’s mind as it is to try to rally people on your own side not to change their minds. That is where I see the “debate” over refugees heading.

If someone can point me to an article on the subject that does not characterize the other point of view as “lunacy” or “irrational,” I would like to see it.

UPDATE: Apparently Megan McArdle and I have similar views.

A commenter asked for my views on the latest campus protests and whatnot. My thoughts:

1. Probably over-played in the media.

2. The specific issues will turn out to be trivial. Like Hillary, I remember the 1960s. And in my high school the big victory for student activism was the agreement to designate a room where students could smoke. A smoking lounge!

3. The really radical students are a small minority. The most radical students are barely tolerated by the vast majority of students.

4. All a college administrator has to do to keep protests from getting out of hand is to communicate with reasonable students so that the radical students become isolated. I predict that where you find college administrators who “manage by walking around” and regularly talk to a lot of students, you will not find college protests that make the news.

5. The reason that campus protests do make the news is that college administrators tend to be both spineless and out of touch. They end up caving in to the radical minority, because they do not know how to obtain and use support from the reasonable majority.

5. I trace my own journey from left to right as beginning at Swarthmore College, where the radical students struck me as silly narcissists. I was not alone in having that reaction. I can think of quite a few alumni from my era who are outspoken conservatives or libertarians. The long-run impact of the protests may be to make more conservative converts than radical converts.

1. I usually choose not to react to current events, and to do so only with a lag. Also, I do not think people come to this blog, nor should they, for my random political viewpoints. So this is being written with trepidation.

2. Think of three approaches to the issue of Syrians fleeing the war zone.

a. Make them stay where they are, without helping them.
b. Bring them to the west.
c. Try to protect them in Syria.

My guess is that the most politically popular move would be (a). But I think that (a) would be wrong, and it is good for leaders to spend political capital trying for (b) or (c). In my post yesterday, I tried to make the case for (c), although I am not convinced by it myself. The most I will say is that it is possible that (c) is the least worst option.

3. Some points work better as rhetoric than as arguments. For example, “more people are killed by car accidents than by terrorists.” The thing about accidents is that they are accidental. We do not have to worry about car accidents issuing threats to Washington, DC, or developing and using a capability to inflict mass casualties.

Also, saying that it shameful or un-American to treat Christians but not Muslims as refugees is not quite right, either. There are plenty of conflict situations in which we identify specific threatened ethnic or religious groups as eligible for asylum. If somebody wants to argue that Christians are more threatened than Muslims in the Middle East, that is a case that can be made. Having said that, I favor (b) or (c) for both Muslims and Christians.

4. I fear that there is no one close to President Obama who is capable of voicing dissent regarding either his substance or his tone. He needs somebody to to tell him that people who disagree with him are not necessarily evil or stupid. They are just people who disagree with him.

5. President Obama’s situation today reminds me of that of Neville Chamberlain in early May of 1940, when his government was toppling. I think that if we were in a Parliamentary system, Mr. Obama’s government would fall. I think that, as in Britain in 1940, the general public is more bellicose than the elites. I imagine that Chamberlain felt about his opponents the way that President Obama feels about Republicans, but Chamberlain had the self-control to keep such feelings to himself.

6. I predict that the Obama Presidency will end like a bitter divorce. There will be intense mutual hatred between his remaining supporters and the majority of Americans. This mutual hatred will be one of the most significant features of American politics for a long time.