A 34-year-old “neo-Taleban” leader in Pakistan is now regarded as the most deadly threat to the West, replacing Osama bin Laden as Public Enemy No 1. Baitullah Mahsud, who is suspected of masterminding the assassination of Benazir Bhutto, the Pakistani politician, was named yesterday as the most significant non-state threat to global security to have emerged in the past 12 months.

Nigel Inkster, the former deputy chief of the British Secret Intelligence Service (MI6), revealed that the neo-Taleban under the leadership of Mahsud were suspected of having been involved in terrorist plots in Britain and Spain.

“There is some evidence they were involved with the assassination of Benazir Bhutto and that they have dispatched terrorists to the United Kingdom and Spain,” Mr Inkster said.

Last month the Spanish police foiled a plot by ten Pakistani and two Indian terrorist suspects to plant explosives on the Metro in Barcelona. Anti-terrorist officers from Scotland Yard detained six Pakistanis who flew from Barcelona to Gatwick two weeks ago after a tip-off from the Spanish. They were questioned and deported.

The revelation that the most extreme elements of the Taleban in Pakistan had turned their focus towards the West and foreign forces in Afghanistan followed claims by President Bush last year that the Taleban posed a global threat. His remark was dismissed largely in Europe.

Mr Inkster was speaking at the release of The Military Balance, an annual publication of the International Institute for Strategic Studies (IISS), of which he is director of trans-national threats and political risk. He was asked which non-state organisation had emerged as the most serious threat and without hesitation identified Mahsud and his neo-Taleban extremists. International terrorism, he said, remained a growth industry and the neo-Taleban — the new generation of the former Afghan rulers — had earned the dubious honour of making the most progress.

Mahsud, who has been branded a senior al-Qaeda terrorist by the Pakistani authorities, lives in South Waziristan, a remote tribal region that borders Afghanistan. The Pashtun and warlord commander is considered by Pakistani security and intelligence services to be a main suspect in the assassination of Ms Bhutto in December.

Mr Inkster, who retired from MI6 a year ago, said that the neo-Taleban groups in the tribal areas of Pakistan could become a global menace.

John Chipman, director-general of the IISS, said that there was a growing security risk in Afghanistan and that there had been a rise in the number of suicide bombings.

“There were more than 140 attacks last year. Some, such as the attack on the Serena Hotel in Kabul [on January 15], showed unusual sophistication in planning and execution. We can expect more,” he said.

The insurgency in Afghanistan, he said, was “given impetus by the instability in Pakistan, which allows fighters to operate from the relative safety of the tribal areas”.

Dr Chipman said that it was important to let President Karzai make his own decisions on security and not to be seen to be led by members of the Nato force in Afghanistan.

Relations between the Nato-led International Security Assistance Force and President Karzai have deteriorated in recent weeks after the Afghan leader’s criticism of the British and US military efforts in the south, and his blocking of Lord Ashdown of Norton-sub-Hamdon, the former Liberal Democrat leader, as a United Nations super-envoy for Afghanistan.

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