Perhaps there is something to be learned from that view, namely that — the democracy project having failed — our best strategy is a quarantine. Middle Eastern occupations are not going to prevent another 9/11, but border control and immigration reform would go a long way toward achieving that. Visitors who are coming from jihadist hot spots, or who have some connection with them, should be subject to an extraordinary degree of scrutiny and supervision. Student visas, in particular, should be severely restricted: Access to an American university education is a coveted commodity, and denying it is our version of an oil embargo. Beyond that, immigration from the Middle East to the United States should be radically curtailed. That such actions would unfairly burden some citizens of those countries should be considered at most secondary to the fact that they would protect citizens of this country. Terrorism requires terrorists to be in proximity to targets. If the Middle East is indeed to be an exporter of terrorism and violence, we need not be an importer of it.

President Bush was not wrong in his desire to take the fight to the enemy; this was, in fact, an admirable inclination. But a more effective and prudent strategy would be to exclude the enemy rather than seek him out. Our main interest in Iraq and Afghanistan was terrorism, and terrorism can be contained by means other than pitched battles and infantry divisions. There is no army in the Islamic world even within a generation of being able to face the U.S. military without being almost instantly annihilated. (Iran’s nuclear program is a different and acute concern.) The so-called law-enforcement approach to counterterrorism has a bad name among conservatives, but in fact our police and intelligence agencies at home are far better suited to preventing terrorist spectaculars than is a Marine Expeditionary Brigade abroad. Between intelligent domestic defenses and pitiless small-scale operations abroad that continue to make jihad a dangerous business, we have a much better chance of achieving our goals than we did through occupation and nation-building in nations that resolutely do not wish to be built.