Published by the London School of Economics, the report on Sunday said that Pakistan's Inter-Services Intelligence agency (ISI) has an "official policy" of support for the Taliban.
It claims the ISI provides funding and training for the Taliban, and that the agency has representatives on the so-called Quetta Shura, the Taliban's leadership council, which is believed to meet in Pakistan.
The report is based on interviews with Taliban commanders in Afghanistan, and was written by Matt Waldman, a fellow at Harvard University.
US officials have long suspected a link between the ISI and the Taliban, but those suspicions are rarely confirmed.
"Pakistan appears to be playing a double-game of astonishing magnitude," the report said.
A Pakistani diplomatic source dismissed the report as "naive".
The report also links high-level members of the Pakistani government with the Taliban.
It claims Asif Ali Zardari, the Pakistani president, met with senior Taliban prisoners earlier this year and promised to release them. Zardari reportedly told the detainees they were only arrested because of American pressure.
"The Pakistan government's apparent duplicity - and awareness of it among the American public and political establishment - could have enormous geopolitical implications," Waldman said.
"Without a change in Pakistani behaviour it will be difficult if not impossible for international forces and the Afghan government to make progress against the insurgency."
Afghan officials have long been suspicious of the ISI's role.
Amrullah Saleh, the former director of Afghanistan's intelligence service, told Reuters last week that the ISI was "part of a landscape of destruction in this country". Saleh resigned last week over a dispute with Hamid Karzai, the Afghan president.
PETALING JAYA, June 13 — Datuk Zaid Ibrahim believes the economy and not race would determine Pakatan Rakyat’s fortunes in the next general elections, but warned that the opposition coalition has yet to wake-up to this reality.
The question of race has been a hallmark of Malaysian politics, plaguing most peninsula-based parties on both sides of the political divide, but the Kelantan-born lawyer said Pakatan Rakyat (PR) must transcend such thoughts.
“Malays and non-Malays are concerned with the economy, education and jobs,” the former Umno minister told The Malaysian Insider yesterday.
Zaid, who is now PR’s secretariat co-ordinator, was responding to admissions by PAS leaders that they were losing the support of Malays in their drive to woo non-Malays, made during their annual general assembly in Kota Baru.
He described the statements as “unnecessary exaggeration”, similar to a worry expressed by his own PKR in its congress
We don’t want to be in denial but such statements are exactly what Umno wants to hear,” said Zaid, who narrowly lost the Hulu Selangor Parliamentary by-election in late April.
He said the big issue for Malays since Election 2008, when the ruling Barisan Nasional (BN) lost five states and its traditional two-thirds majority in Parliament, was the emergence of Perkasa led by fellow Kelantanese, Datuk Ibrahim Ali.