From a broader policy viewpoint, the Bush administration's most significant accomplishment, terrorism experts tend to agree, was the 2001 defeat of Afghanistan's Taliban regime and the destruction of Bin Laden's training camps. As noted in "The Terrorists-Are-Dumb Theory" and "The Melting Pot Theory," two-thirds of al-Qaida's leadership was captured or killed. Journalist Lawrence Wright estimates that nearly 80 percent of al-Qaida's Afghanistan-based membership was killed in the U.S. invasion, and intelligence estimates suggest al-Qaida's current membership may be as low as 200 or 300.
A 2007 National Intelligence Estimate stated that Bin Laden had "protected or regenerated key elements of its Homeland attack capability" by establishing a safe haven in Pakistan's tribal borderlands and through the appointment of operational lieutenants. On Feb. 25, Dennis C. Blair, the Obama administration's new director of national intelligence, told Congress that al-Qaida's leaders use this safe haven "as a base from which they can avoid capture, produce propaganda, communicate with operational cells abroad, and provide training and indoctrination to new terrorist operatives." But the Bush administration and Pakistan government responded to al-Qaida's improving capability by stepping up attacks on the tribal borderlands, and these continue under President Obama. According to unnamed Pakistani intelligence officials recently quoted in the New York Times, U.S. pilotless drone attacks are reducing the likelihood of an al-Qaida attack against the United States but increasing the likelihood that al-Qaida and the Taliban will destabilize Pakistan (see "The Near-Enemy Theory"), because the drones are killing many civilians along with the terrorists. The Bush administration struggled to keep these two considerations in balance. So will the Obama team.
Georgetown's Bruce Hoffman credits the National Counterterrorism Center, created in 2004, with breaking down much of the interagency resistance to sharing intelligence that proved fatal on 9/11. (See "The Terrorists-Are-Dumb Theory.") New procedures to screen commercial airline passengers and consolidate terrorist watch lists surely helped. Even the much-mocked Transportation Security Administration (nicknamed "Thousands Standing Around" in security-conscious Israel) has probably improved security, not because its methods are foolproof but because even a small increase in the risk of detection can make a big difference in a would-be terrorist's mental calculus. It's less clear that the doubling of border-patrol agents has had much effect, if only because policing U.S. borders remains a near-impossible task.
One Bush effort whose success is extremely difficult to gauge is the Treasury Department's tracking of terrorist funds. About $262 million in Taliban assets were blocked and then turned over to the new Afghan government after the U.S. invasion, and the Treasury's report on terrorist assets for 2007 (the most recent year for which data are available) lists $11 million in blocked al-Qaida assets (up from $8 million the previous year). According to the Central Intelligence Agency, before 9/11, al-Qaida had an annual budget of $30 million. Virtually none of this came from Osama Bin Laden's personal fortune, which was seized by the Saudis in 1994. As much as two-thirds of the al-Qaida budget may have been funneled directly to the Taliban as protection money. Richard Clarke, former White House counterterrorism chief, told Robert Windrem and Garrett Haake of MSNBC that the $30 million figure was "totally made up." Nobody even pretends to know how much money al-Qaida has now; most of it is probably in cash. The $11 million frozen by the U.S. government may be only a fraction of the amount that enthusiastic donors, exuberant about 9/11, kicked in after the attacks. On the other hand, getting cash-filled satchels to al-Qaida's top officers would surely have posed a steep challenge immediately after 9/11 and remains more difficult than it was before 9/11. On yet another hand, the 9/11 attacks cost only $500,000. Terrorism is a low-overhead business.
The departing Bush administration's claim that deposing Saddam Hussein helped prevent acts of terror in the United States has virtually no adherents, except to the extent that it drew some jihadis into Iraq. (See "The Flypaper Theory.") The Iraq war reduced U.S. standing in the Muslim world, especially when evidence surfaced that U.S. military officials had tortured and humiliated prisoners at the Abu Ghraib prison. The Bush White House fact sheet mentions not at all the Guantanamo internments and the Central Intelligence Agency's torture of terror suspects. That was probably a wise choice. But Vice President Dick Cheney defended these practices in exit interviews as he was leaving the White House, citing specifically the "wealth of information" provided by Khalid Sheikh Mohammed, who was reportedly water-boarded. "There was a period of time there, three or four years ago," Cheney said, "when about half of everything we knew about al Qaeda came from that one source." Capturing Sheikh Mohammed surely helped make America safe, but, as Slate's Dahlia Lithwick noted at the time, almost no one believes torture produces good information, and the number of people who believe it is legal "corresponds almost perfectly to the number of people who could be prosecuted for war crimes because it is not."
The noncontroversial parts of Bush's antiterrorism policies will continue under President Obama. The controversial parts probably won't. That troubles Cheney, who in February toldPolitico, "When we get people who are more concerned about reading the rights to an Al Qaeda terrorist than they are with protecting the United States against people who are absolutely committed to do anything they can to kill Americans, then I worry." If Cheney is right, then we're in greater danger under the Obama administration than we were under the Bush administration. If Cheney is wrong, then U.S. torture policies never provided much safety in the first place and may have made things worse by inflaming our enemies. Indeed, a recent two-part Washington Post piece suggested that abuse suffered by a Guantanamo detainee named Abdallah Saleh al-Ajmi transformed him from a relatively harmless Taliban foot soldier into a dedicated suicide bomber who, after his release, killed 13 Iraqi soldiers and wounded 42 others.
Either way, the government's ability to prevent another 9/11, while certainly greater than it was eight years ago, is surely incomplete. As with the Flypaper Theory, the He-Kept-Us Safe Theory offers cold comfort, because even if you accept every word of it as historically true, there are too many current and future contingencies that it can't address.
[Update, April 6: In the Politico interview, Cheney said that documentary evidence will eventually be made public showing that waterboarding and other tactics promoted by the Bush administration prevented follow-up attacks. It's widely assumed the waterboarded terror suspect Cheney has in mind was Abu Zubaida, the first "high-value" al-Qaida captive. But in a March 29 Washington Post story ("Detainee's Harsh Treatment Foiled No Plots,") Peter Finn and Joby Warrick reported that waterboarding Zubaida yielded no information that prevented any attacks. "Nearly all of the leads attained through the harsh measures quickly evaporated," they wrote, "while most of the useful information from Abu Zubaida—chiefly names of al-Qaeda members and associates—was obtained before waterboarding was introduced," according to "former senior government officials who closely followed the interrogations." The Post, echoing earlier reporting by Ron Suskind, further reported that Zubaida was never as "high-value" a captive as the Bush administration let on.]
Next: "The Electoral-Cycles Theory," in which we'll consider whether al-Qaida times its attacks to occur before or after big national elections.