A COUPLE of weeks ago Pakistan completed an ambitious assault on the polio virus. This is a country where many people entertain a widespread conspiracy theory that vaccinating for polio is a Western plot to curb Muslim fecundity. Thugs from the Pakistani Taliban have targeted and killed health workers, and in late 2012 the UN suspended its anti-polio efforts right across the country.

But alarmed by how Peshawar had become the largest “reservoir” of the disease in the world, officials set out to banish it from the north-western city’s crowded, squalid streets. They reckoned they needed to vaccinate 760,000 children, giving them drops on a certain day every week for 12 weeks. Some 8,000 health workers hit the streets each weekend, accompanied by around 5,000 police to protect them.

It was a success. In a country not known for its organisational prowess, large numbers of children were vaccinated, no one was killed and the city’s immunity was significantly boosted.

Despite Peshawar’s performance, Pakistan continues to underperform in the fight against a terrible disease that can kill or permanently disable its young victims. On May 5th the World Health Organisation (WHO) announced serious alarm over a major global outbreak of the disease: 74 cases reported so far this year, in eight countries. It called on Pakistan, along with Cameroon and Syria, to require all residents to be vaccinated for the disease before travelling abroad. The Peshawar strain has already cropped up around the Middle East. All the more mortifying for Pakistan is that in March India was declared polio-free. Five years ago India accounted for nearly half of all the world’s infections.

Pakistan has seen a sharp increase in polio cases this year: 59, compared with six cases in the same period in 2013. Nearly all of those were in or close to the tribal areas of North Waziristan and South Waziristan, borderlands near Peshawar where the Taliban is strong and government rule minimal or non-existent. Hardly any children have been vaccinated there.

In those badlands the government is currently pinning its hopes on peace talks with the Pakistani Taliban, but they are unlikely to go anywhere. The prime minister, Nawaz Sharif, is deeply reluctant to back a military campaign to regain control of North Waziristan, the Taliban’s main stronghold, in part because he fears that it will suck violence into Pakistan’s heartland.

Mr Sharif’s national polio co-ordinator, Ayesha Raza Farooq, is attempting to make progress all the same. She says the government is now working on “firewalling” the tribal areas, with checkpoints where children crossing into the rest of Pakistan can be vaccinated. Still, just two years ago the world seemed tantalisingly close to eradicating polio for good. Pakistan’s trouble with its militants means it is going to take longer.