The US ambassador to Afghanistan sent a top-secret cable to Washington last month warning that the existence of enemy havens in Pakistan was placing the US strategy in Afghanistan in jeopardy, The Washington Post reported late Friday.
Citing unnamed US officials, the newspaper said that the cable, written by Ambassador Ryan Crocker, amounted to an admission that US efforts to curtail activities in Pakistan by the Haqqani network, a key Taliban ally, were failing.
Pakistan's relationship with the United States drastically deteriorated last year over the covert American raid that killed Osama bin Laden and US air strikes that killed 24 Pakistani soldiers along the Afghan border.
The administration of President Barack Obama plans to end combat operations in Afghanistan by 2014.
In past years, US military officials have argued that the best defense against Pakistan insurgent sanctuaries was a stronger Afghan army and government, the newspaper report said. But with the US drawdown looming, the need to directly address the sanctuaries seems more urgent.
"The sanctuaries are a deal-killer for the strategy," The Post quoted a senior defense official as saying.
The Haqqani network is responsible for some of the larger and more dramatic attacks on Kabul, including one on the US Embassy last year, the paper said.
The group's patriarch, Jalaluddin Haqqani, was a major mujaheddin fighter in the CIA-backed effort to expel the Soviets from Afghanistan in the 1980s.
He has relinquished control to his son, Sirajuddin, who carries a $5 million US bounty on his head and runs day-to-day operations from the network's Pakistani base in Miran Shah, the paper said.
The location has given the Haqqani leadership a measure of protection, according to The Post. The CIA has refrained from launching missiles at known Haqqani targets, out of concern for civilian casualties and the backlash that could ensue.