At first glance, the news that the Taliban have reportedly decided to ban polio vaccinations for 160,000 children in tribal regions of Pakistan as a way of protesting ongoing drone attacks by the U.S. might seem foolishly counter-productive. As Ed Yong put it in on Twitter, "Taliban to US: "If you don't stop killing our kids w/ drones, we'll kill them with polio." World to Taliban: "Erm...""

But a quick look at the numbers shows that the Taliban are NOT actually shooting themselves in the foot, so to speak. They are, in fact, attempting to hold the world hostage.

The threat is not to Pakistani children but to the children of the rest of the world--who might develop paralytic polio if the infection is not contained in the three countries where it continues to be endemic--Pakistan, Afghanistan and Nigeria.

Let me explain. According to the World Health Organization, there were 49 cases of clinically relevant polio in Pakistan in 2011. Most of them presumably survived since the mortality rate for pediatric polio ranges from 2 percent to 5 percent (pdf). Going strictly by the numbers, under the 5 percent worst case scenario, you'd expect 3 of the 49 children who developed paralytic polio to die of the disease.

Now for the other half of the equation. According to the London-based Bureau of Investigative Reporting, at least 75 civilians died in US drone attacks in Pakistan in 2011--six of them children.

So, in a cold-hearted balancing of an equation measured in children's deaths, the Taliban bargain of polio vaccines for drone attacks actually works in their favor: six children potentially not killed by drones minus three children killed by polio puts them ahead three children.

Of course, anyone who knows anything about polio understands that the Taliban's true threat is that its actions in denying vaccination could help spread polio to other countries. Indeed, as an article by Helen Branswell pointed out in May, China last year reported its first cases of polio in more than a decade. The viral strains that caused the illness were traced via genetic testing back to Pakistan.