By Mark Hosenball
WASHINGTON (Reuters) - U.S. officials say there is mounting evidence that Pakistan's chief intelligence agency has been encouraging a Pakistan-based militant network to attack U.S. targets.
The allegations, if fully confirmed, heighten a painful dilemma for President Barack Obama's administration. Washington is under growing political pressure to take action against the Haqqani network after a spate of deadly attacks U.S. officials have attributed to it. These include last week's strike against the American Embassy in Kabul, Afghanistan.
Some U.S. intelligence reporting alleges that Pakistan's Inter Services Intelligence directorate (ISI) specifically directed, or urged, the Haqqani network to carry out the September 13 attack on the embassy and a NATO headquarters in Kabul, according two U.S. officials and a source familiar with recent U.S.-Pakistan official contacts. However, officials cautioned that this information is uncorroborated.
Another U.S. official familiar with internal government assessments said that at the very least, the available intelligence strongly suggests the ISI has been egging on elements of the Haqqani network to launch attacks at American targets in the region.
While American officials have aired allegations of ties between the ISI and the Haqqani network in recent days, they have not publicly cited evidence that the Pakistani agency, or elements of it, urged its proxy to attack U.S. targets.
While the ISI's motives in any such attacks are not clear, Pakistan has long wanted to play a major role in Afghanistan's future after the departure of NATO troops, and to counter what it sees as the growing influence there of arch-rival India.
This week, top U.S. officials, including Joint Chiefs of Staff chairman Admiral Mike Mullen, demanded that Pakistan's leaders take action against the Haqqanis, who are based in that country's tribal areas and are considered among the most dangerous insurgent groups in the Afghanistan-Pakistan region.
Still, despite the threats and an intensified campaign of violence that threatens U.S. efforts to stabilize Afghanistan, the Obama administration has few options for increasing pressure on Pakistan and none of them are good.
After years of efforts to cajole, coax and threaten Pakistan into cracking down on a host of militants operating from within its borders failed to bear fruit, U.S. officials are exasperated.
One alternative -- another cross-border raid, like the U.S. special forces mission that killed al Qaeda leader Osama bin Laden in May -- may be tempting in some quarters of the U.S. government. But the risks are high and the backlash from Pakistan would be fierce, almost certainly harming what counter-terrorism cooperation exists.
"The administration has thrown everything at this -- high-level meetings, tons of money, all of these overtures, and it hasn't gotten us anywhere," said Caroline Wadhams, a security analyst in Washington.
"This can't go on forever," she said, "but the problem is that we have so little leverage."
The long-simmering tension between the sometime allies, sometime adversaries came to a head last week after the brazen attack on the U.S. Embassy in Kabul. It was a major blow as Obama hopes to nudge Afghanistan toward stability and gradually bring home U.S. forces after a decade of war.
Since then, American officials, including Obama's ambassador in Islamabad and Mullen, his top military officer, have issued unusually blunt criticisms of Pakistan's failure to curb the Haqqani group -- and made frank statements accusing Islamabad of links to the group.
Mullen, in a speech to the Carnegie Endowment for International Peace, said Tuesday he had pressed Pakistan's army chief in a four-hour conversation on Friday to break the country's links with the Haqqanis.
"We covered ... the need for the Haqqani Network to disengage, specifically the need for the ISI to disconnect from Haqqani and from this proxy war that they're fighting," Mullen said.
The Haqqanis, just one of a host of militant groups that have used western Pakistan as a base for attacks in Afghanistan, are seen as allied to both al Qaeda and the Afghan Taliban. Supported at times in the past by the CIA, they have had long-standing ties to the ISI.
On Tuesday, regional tensions soared even higher when a suicide bomber killed Burhanuddin Rabbani, the former Afghan president who had headed efforts to secure a peace deal with the Taliban.
While responsibility for the attack remains unclear, the shocking assassination threatened to do even more to reverse a tentative thaw in perpetually dismal U.S.-Pakistani ties a few months after Osama bin Laden was killed near Islamabad. The initial conclusion of U.S. government experts is that Rabbani's assassination was carried out by Afghan Taliban and had no connection to the Haqqani network.
Vali Nasr, who until this spring was a senior official in the U.S. State Department's Afghanistan-Pakistan office, said efforts to prompt Pakistani action against militants with increased public pressure had fallen short.
"They are not blinking," he said.
(Editing by Warren Strobel and Christopher Wilson)