One man does not a militancy make, but the possible killing of Baitullah Mehsud, Pakistan's most wanted man, could mark a major strike in the fight against extremists. For Islamabad and Washington it may also open a window that allows them to bring other leaders of the Pakistan Taliban to their side.

The assassination of the former fitness instructor by a missile fired from a CIA drone, following as it does close on the heels of the Pakistan army's success in the Swat Valley, could scarcely have been imagined just six months ago.

Then, with Pakistan facing a wave of suicide attacks directed by Mehsud, and the former tourist haven barely 60 miles from Islamabad under the control of his Taliban allies, the momentum appeared firmly with the militants. With Mehsud now dead, parts of Swat cleared and the army pressing at the militant stronghold of South Waziristan, the balance has shifted. "It's a great boost to the morale of the security forces," said Rasul Bakhsh Rais, a Lahore-based analyst.

The death of the man who emerged from a lesser branch of the Mehsud tribe to be named in 2007 as the 'emir' of a coalition of militant groups known as the Tehrik-e-Taliban Pakistan (TTP) would undoubtedly leave a vacuum.

While his image as public enemy number one may have been partly created by the US and Pakistani govern­ments, the man who refused to allow his face to be photographed was more than just a figurehead. He was a skilled tactician and a ruthless leader ready to strike against both "enemy targets" and rivals. Earlier this year an assassin dispatched by Mehsud killed Qari Zainuddin, another Taliban leader and a challenger.

He was also a consummate networker of militant groups. Several attacks earlier this year in Lahore involved extremists from the Punjab, something that revealed a perilous nexus between the tribal areas and the country's heartland.

There may be revenge attacks, just as the siege of Islamabad's Red Mosque in 2007 and the death of its militant cleric, Abdul Rashid Ghazi, led to a spate of assaults by Mehsud and his followers. Farzana Shaikh, author of Making Sense of Pakistan, said: "Taliban groups may well want to exact revenge for Mehsud's death. That could mean a new wave of attacks."

At the same time, his killing may allow Pakistan to reach out to other Taliban elements who may previously have felt obliged to offer fealty to Mehsud. The security services have already been trying this with varying levels of success.

The attack has renewed attention on the US policy of drone strikes. Publicly condemned but privately supported by Pakistan, such strikes have markedly increased since Barack Obama came to office with a new policy of targeting not just militants responsible for cross-border raids in Afghanistan but those who threatened havoc within Pakistan and the wider region. It was this switch in tactics that directly led to the attack on Mehsud.

There will be no let-up in such strikes. Whoever is selected to succeed the militant leader will be aware that they could face a similar fate.