What little we know of the attempted explosive attack on Times Square suggests a crudely designed and constructed vehicle bomb, intended to target street-side crowds in an iconic American location. A dubious claim of responsibility was quickly issued by the spokesman for Tehrik-e-Taliban Pakistan (the so-called Pakistani Taliban).
This attempted attack reveals how easy it can be to deliver a car bomb -- or at least a vehicle loaded with combustible materials -- into the center of a bustling urban area. Reports indicate the payload in this instance was a combination of gasoline, propane, and inert fertilizer, to be detonated with fireworks using alarm clocks as timers. All of these materials are legal to purchase, own, and transport, save perhaps the fireworks in some states. And these substances are so common that it is both easy to obtain them and hide their origin. The latter factor -- the inability of authorities to trace the bomb components -- appears important to an assailant who also tried to conceal identifying information about the vehicle by removing serial numbers and using stolen license plates.
However, it also shows how difficult it can be to actually accomplish a full explosion. Producing a complete detonation has been the most important hurdle for a number of failed terrorist bombers, including Christmas Day bomber Umar Farouk Abdulmutallab, shoe bomber Richard Reid, the bombers of the June 30, 2007, Glasgow Airport attacks, and the bombers of the July 21, 2005, attacks against the London public transit system. While all of these attackers in some way initiated their bombs, none of them caused the explosions -- or the accompanying devastation and loss of life -- that they intended.
Accomplishing catastrophic effects is difficult because the detonation of a large explosion begins with a very small ignition and progressively (though rapidly) grows into something much bigger. It happens in an instant, but it happens by design and in sequence. Done properly, each step in the chain reaction occurs because of a deliberate plan to build upon the energy released by the preceding step, culminating in the explosion of the main charge. Trying to explode a propane cylinder with a firecracker, as the Times Square attacker did, is a bit like trying to topple a refrigerator with a domino.
Regardless, propane, gasoline, fireworks, and some fertilizers are all energetic materials that when ignited correctly could have produced the "significant fireball" described by New York City Police Commissioner Raymond Kelly. Compressed propane can explode spectacularly, and in it has in places like Iraq, where insurgents used fireballs to improve the theatrical effect of videotaped attacks against American troops. Propane has also been observed in bombing attempts in Germany in 2006 and Scotland in 2007.
The choice of inert fertilizer is either a simple mistake or another attempt to conceal potential evidence. If the bomber suspected that the right kind of fertilizer might contain taggants that can help authorities identify the fertilizer's source and seller, then he might have looked for a less traceable, albeit ultimately ineffective, alternative.
It is extremely unlikely that a lone actor, with no direct training or applicable expertise, can learn all that is necessary to conduct destructive bombings from third-party sources like illicit instructions culled online. The task requires a safe and unobserved place to prepare and rehearse, as well as the assistance of trusted conspirators and some formal training. Some reports and statements are starting to indicate that this person did not operate alone and may have acted with support from abroad. So this attack may demonstrate -- once again -- that an assailant with all of these advantages can still fail.
Timothy McVeigh, who learned about explosive principles on military bases and relied on at least one if not two trusted assistants, understood how to design explosive sequences using energetic fertilizer and fuel oil as a main charge. While his attack was designed to destroy the Murrah Federal Building and kill its occupants, the evidence indicates the Times Square attempt aimed mostly to create a spectacle and a sense of panic. Bombings like McVeigh's have catalyzed significant public support for taggant identification of fertilizers and explosives, though opponents of taggants resist for many reasons, such as privacy concerns. Perhaps in this case taggants served to deter the bomber from using a concentrated fertilizer.
International terrorist organizations, as well as state sponsors of terrorism, have historically helped enable successful bombings. Superficially, the intent and target of this attack do seem aligned with that of several international Islamist groups. Like the four failed attacks above, these attackers struck at very public places to kill or maim many random American or British citizens. So it is possible that this attack was at least inspired by jihadi zeal.
But the Times Square incident is different in one critical respect from the four examples of failed jihadi bombings above: Whereas the other attacks were planned as suicides, the assailant seems to have intended to survive his bombing, as demonstrated by the empty Nissan Pathfinder left at the scene. The aspiration to martyrdom associated with al Qaeda and similar movements does not appear to have motivated the bomber in this instance. The reasons for this key difference are as yet unclear.
Taken altogether, the dubious claims of international responsibility, the defective conceptualization of the attack, the nefarious intent, the choice of target, and the apparent preference for survival indicate inexperienced, enthusiastic, unsure, and isolated actor(s), trying more than anything else to make a political statement to American and global audiences.
Alec Barker is a national security analyst and consultant based in Washington, D.C., and the author of a New America Foundation Counterterrorism Strategy Initiative research paper called "Improvised Explosive Devices in Southern Afghanistan and Western Pakistan, 2002-2009." He is solely responsible for the content of this piece.