Here is the bad news: Last week, terrorists linked to an al-Qaida cell in Yemen disguised powerful explosives as printer cartridges, inserted them into packages, and smuggled them onto cargo planes bound for the United States. The packages are clearly the work of someone with expertise: The president's counterterrorism adviser, John Brennan, has declared that "[t]he individual who has been making these bombs ... is a very dangerous individual, clearly somebody who has a fair amount of training and experience."
Now here is the good news: The explosive chemical inserted into the package was PETN, Pentaerythritol tetranitrate. PETN was first synthesized in 1891, was patented in Germany in 1912, and has been used since World War I. PETN has been around for a long time, in other words—and it still isn't that easy for would-be terrorists to manipulate. PETN was the explosive that the shoe bomber, Richard Reid, failed to set off in 2001. PETN was also the explosive that the underwear bomber, Umar Farouk Abdulmutallab, failed to set off last Christmas. These latest bombs may also havefailed:They seem to have been configured as "cell phone" bombs, not as ordinary package bombs, yet no phone signal would have been able to reach them over the Atlantic. Investigators are still trying to understand how the bombs were meant to be detonated. But it is possible that they simply didn't work as planned.
PETN, in other words, isn't a weapon of mass destruction. It can take down a plane but not a city. It requires a fair amount of training and experience to deploy, but not advanced degrees in chemistry or physics. It is far from fail-safe. Which is exactly my point: If al-Qaida terrorists are stuffing PETN into underwear or packages, that must mean that they do not have access to cutting-edge biological research or nuclear bomb components. On the contrary, they remain strangely fixated on airplanes and far behind the technological times.
Clearly, this latest incarnation of al-Qaida is not benign: Islamic fundamentalist terrorism remains a threat, and the terrorists responsible for this latest attempt appear to be probing the international aviation system, looking for weaknesses. One day they may succeed. Yet although they are dangerous, although they are ruthless, these package bombs prove that al-Qaida, at least in its desert hideouts on the Arabian peninsula, does not pose a serious, existential security challenge to the United States.
There are plenty of such challenges around. Nuclear technology has spread to Iran, North Korea, and Pakistan, among others. Radioactive chemicals are widely available—and have indeed been used, probably by Russian agents, in the poisoning of ex-KGB officer Alexander Litvinenko in London in 2006—as are other forms of poison gas. The recent discovery of Stuxnet, a computer worm designed to target critical infrastructure, might also herald the coming of the age of cyberwarfare. Already, hundreds of what appear to be coordinated attacks on sensitive cybertargets in the United States and Europe are repulsed every week, and many seem to come from Russia or China. Richard Clarke, one of Brennan's predecessors, has written that China has "systematically done all the things a nation would do if it contemplated having an offensive cyber war capability," even if it doesn't intend to launch such a war right now.
It's a list that needn't frighten anybody but that should lend some perspective to the debate about al-Qaida, Yemen, and airport and cargo security that will surely follow this week's midterm elections. If the best al-Qaida's remaining cells can do is hide PETN, a 19th-century explosive, inside a printer cartridge, then perhaps we have already succeeded—far more than we usually realize—in destabilizing at least this particular terrorist threat. We should continue to support the security services and counterterrorism experts who prevented this tragedy and will prevent others. But we shouldn't let al-Qaida take too much public attention, diplomatic energy, and government funding away from the more complicated, and more dangerous, challenges of the future.