Faisal Shahzad, the Pakistan-born American citizen arrested on suspicion of being Times Square's would-be May Day bomber, did not act alone. Reportedly he's told authorities he received bomb training in Waziristan, a Taliban and al-Qaida stronghold. In Pakistan, a man named Muhammad Rehan, who was seen with Shahzad on a recent visit, has been arrested; Rehan's mosque is reportedly linked to Jaish-e-Mohammed, the same al-Qaida affiliate that five young Muslim Americans from Alexandria, Va., contacted in Pakistan this past December, leading to their arrest.
It would appear that a second shoe has dropped.
In February 2009 I published a Slate series ("Why No More 9/11s?") exploring various theories as to why the United States had never suffered another large-scale foreign terror attack after Sept. 11, 2001. I arranged the theories along an axis that ran from "worry a little" to "worry a lot." Most of the "worry a lot" theories (Bush kept us safe; it's all about electoral cycles), seemed reassuringly far-fetched, but the last and most worrisome theory, a time-space calculation by a couple of big-brained analysts at the Rand Corp., gave me pause. The "space" part of the calculation made the simple point that proximity to a violent extremist enemy and easy access to international borders increased your vulnerability to (hence frequency of) terror attacks. That's one reason why Israel (nearby and only 85 miles wide) suffers from terrorist attacks more frequently than the United States (far away and 3,000 miles wide). It's actually quite difficult to attack a sprawling country surrounded by ocean on the other side of the world.
But the difficulty was not constant, because after a country suffered a terrorist attack it was put on its guard—for instance by tightening its borders, stepping up its intelligence-gathering, and devoting military resources to tracking down and killing the enemy. We can argue about how well the United States has done that, and at what cost, but without question the nation rapidly became more difficult for terrorists to attack after Sept. 11 than it was before. But over time (I wrote),
these security measures slacken, creating new opportunities for attack. In Jerusalem, [RAND economists Claude] Berrebi and [Darius] Lakdawalla found that after a terror attack the risk of a follow-up attack begins to increase after only two incident-free months. "This suggests," they conclude, "that long periods of quiet actually indicate elevated risk for sensitive areas." Berrebi and Lakdawalla are restating the familiar war-movie cliché in which two soldiers stand guard over a peaceful nighttime landscape. "It's quiet," says one. "Yeah," says the other. "Too quiet." Then the enemy emits a battle cry and the fighting begins.
If Israel took only two months to go from peak to trough, how long would the United States take? I resisted any temptation to speculate in my series, but the previous "big" foreign-terror incident in the United States before 9/11 was the World Trade Center car bombing in Feb. 1993. That's eight years and seven months from peak to peak. The foiled Times Square attack occurred eight years and eight months after 9/11. That's pretty close!
We should resist the urge to make too much of this numerological precision. The unexploded bomb in Times Square is not the first major foreign-terror near-miss since 9/11 and Richard Reid's follow-on attempted shoe bombing (in December 2001). That distinction probably belongs to Najibullah Zazi's attempted bombing of the New York subway system in Sept. 2009. Before Zazi, post-9/11 terror plots inside the United States were amateurish affairs stopped well before the public faced any danger; many were two-person operations in which the collaborator was an FBI agent or informant conducting a sting. But Zazi was an authentically dangerous al-Qaida-trained terrorist who came uncomfortably close to carrying out his attack. Three months later, Umar Farouk Abdulmutallab (aka the underpants bomber) allegedly tried and failed to detonate a bomb on a Northwest Airlines flight from Amsterdam to Detroit. Abdulmutallab, like Zazi, was trained by al-Qaida and came even closer to carrying out his plan. Shahzad, the Times Square suspect, is looking very much like a third authentically scary al-Qaida terrorist. Which (if precision's your thing) would actually make him not the second shoe, but the fourth.
The point is that Zazi, Abdulmutallab, and Shahzad are probably more than just a statistically quirky cluster. They constitute circumstantial but compelling evidence that al-Qaida has stepped up its efforts to attack the United States in response to a perceived or real lowering of our guard. Before Dick Cheney blames this on Barack Obama, let me point out that if the peaks are Sept. 2001 and May 2010, then the trough (i.e., the moment of maximum security) would be around Jan. 2006. That, in turn, would mean that the risk of a terror attack climbed precipitously during the last three years of George W. Bush's eight-year administration. (Hard-liners might answer that our defenses started to slacken almost immediately after the Nov. 2006 resignation of Defense Secretary Donald "There aren't any good targets in Afghanistan" Rumsfeld.)
If Berrebi and Lakdawalla are right, then blame does not lie with either Bush or Obama. Rather, it lies with human nature and a simple, predictable tendency to become more vulnerable to terrorist attack (or at least to be thought by terrorist enemies to have become so) as the memory of a previous attack starts to fade. The good news is that so far, none of the bombs has gone off.
Update, May 5: The Los Angeles Times confirms that Muhammad Rehan, with whom Shahzad travelled in Pakistan, is a member of the al-Qaida affiliate Jaish-e-Mohammed.
Slate V: Audio from the alleged bomber's plane:
E-mail Timothy Noah at firstname.lastname@example.org.