http://www.nytimes.com/2010/12/18/world/asia/18pstan.html?_r=1&pagewanted=all WASHINGTON â€” The Central Intelligence Agencyâ€™s top clandestine officer in Pakistanâ€™s capital, Islamabad, was removed from the country on Thursday amid an escalating war of recriminations between American and Pakistani spies, with some American officials convinced that the officerâ€™s cover was deliberately blown by Pakistanâ€™s military intelligence agency. The American spyâ€™s hurried departure is the latest evidence of mounting tensions between two uneasy allies, with the Obama administrationâ€™s strategy for ending the war in Afghanistan hinging on the cooperation of Pakistan in the hunt for militants in the mountains that border those two countries. The tensions could intensify in the coming months with the prospect of more American pressure on Pakistan. As the cloak-and-dagger drama was playing out in Islamabad, 100 miles to the west the C.I.A. was expanding its covert war using armed drones against militants. Since Thursday, C.I.A. missile strikes have killed dozens of suspects in Khyber Agency, a part of the tribal areas in Pakistan that the spy agency had largely spared until now because of its proximity to the sprawling market city of Peshawar. American officials said the C.I.A. station chief had received a number of death threats since being publicly identified in a legal complaint sent to the Pakistani police this week by the family of victims of earlier drone campaigns. The American officials said they strongly suspected that operatives of Pakistanâ€™s powerful spy service, the Directorate for Inter-Services Intelligence, had a hand in revealing the C.I.A. officerâ€™s identity â€” possibly in retaliation for a civil lawsuit filed in Brooklyn last month implicating the ISI chief in the Mumbai terrorist attacks of November 2008. The officials, who spoke on the condition of anonymity, did not immediately provide details to support their suspicions. The mistrust between the C.I.A. and ISI, two uneasy but co-dependent allies, could hardly come at a worse time. The Obama administrationâ€™s Afghan war strategy depends on greater cooperation from Pakistan to hunt militants in the countryâ€™s western mountains, and yet if Pakistan considers Washingtonâ€™s demands excessive, it could order an end to the C.I.A. drone campaign. â€œWe will continue to help strengthen Pakistani capacity to root out terrorists,â€ President Obama said Thursday in a briefing on the war strategy. â€œNevertheless, progress has not come fast enough. So we will continue to insist to Pakistani leaders that terrorist safe havens within their borders must be dealt with.â€ The job of the C.I.A. station chief in Islamabad is perhaps the spy agencyâ€™s most important overseas post, one that requires helping oversee the agencyâ€™s covert war and massaging its often testy relationship with the ISI. That relationship has often frayed in recent years. American officials believe that ISI officers helped plan the deadly July 2008 bombing of the Indian Embassy in Kabul, Afghanistan, as well as provided support to Lashkar-e-Taiba militants who carried out the Mumbai attacks later that year. Michael J. Morell, the C.I.A.â€™s deputy director, met Thursday with Pakistani officials in Islamabad, but American officials said his visit was not the result of the station chiefâ€™s case. The lawsuit filed in Brooklyn last month, brought by families of American victims of the Mumbai attacks, names the ISI chief, Lt. Gen. Ahmed Shuja Pasha, as being complicit in the attacks. The suit asserts that General Pasha and other ISI officers were â€œpurposefully engaged in the direct provision of material support or resourcesâ€ to the planners of the Mumbai attacks. A senior Pakistani official, also speaking on the condition of anonymity, said that the Pakistani government â€œbelieves that the suit in New York does not have a sound legal basis, and is based on conjecture.â€ â€œWe did not need to retaliate,â€ he said. â€œAs far as the government of Pakistan and the ISI are concerned, we look forward to working with the Americans in securing the world from transnational threats, especially the shared threat of terrorism.â€ The legal complaint in Pakistan that identified the station chief was filed Monday over drone attacks that killed at least four Pakistanis. The complaint sought police help in keeping the station chief in the country until a lawsuit could be filed. The C.I.A.â€™s decision to remove the station chief from Islamabad was first reported Friday morning by The Associated Press. The C.I.A. officerâ€™s name was revealed last month in a news conference by Mirza Shahzad Akbar, the lawyer who filed the complaint this week. Soon afterward, the name began appearing on a number of Pakistani Web sites generally believed to have a close association with the ISI. One Web site mentioned the C.I.A. officer on Dec. 14 and asked readers to track down pictures of him. The New York Times generally does not identify American intelligence operatives working undercover. Mr. Akbar, the lawyer who brought the case against the C.I.A., said it would continue despite the station chiefâ€™s absence. He is representing Kareem Khan, a resident of North Waziristan who said that his son and brother were killed in a drone strike. A vast majority of C.I.A. drone strikes in the tribal areas have occurred in North Waziristan. Mr. Khan is seeking $500 million in compensation, and accusing the C.I.A. officer of running a clandestine spying operation out of the United States Embassy in Islamabad. â€œMy brother and son were innocent,â€ Mr. Khan said in a recent interview. â€œThere were no Taliban hiding in my house.â€ Western and Pakistani intelligence officials said, however, that the drone attack also killed Haji Omer, a senior commander allied with the Haqqani militant network and Al Qaeda. Mr. Akbar said that he did not believe that the station chief had been removed from Islamabad for his security. â€œObviously, his name had come out in the open, and maybe he feared police action or an action by the Supreme Court,â€ Mr. Akbar said in an interview. American officials disagreed. The threats to the station chief â€œwere of such a serious nature that it would be imprudent not to act,â€ according to a United States intelligence official who spoke on the condition of anonymity. George Little, a C.I.A. spokesman, would not confirm that the station chief had to leave Pakistan, but did say that â€œstation chiefs routinely encounter major risk as they work to keep America safe,â€ and that â€œtheir security is obviously a top priority for the C.I.A., especially when thereâ€™s an imminent threat.â€ Meanwhile, the C.I.A. has continued to pummel parts of the tribal areas with missiles. On Thursday, a C.I.A. drone launched a strike in the Tirah Valley of the Khyber Agency, where Pakistani militants are believed to have fled to escape military operations in other parts of the tribal belt. Three more strikes followed on Friday, a Pakistani government official said, killing dozens of militant suspects. Attacks in Khyber are uncommon. Pakistani officials have tried to dissuade the Americans from attacking Khyber and Mohmand Agency, fearing that strikes in those areas could fuel violence in Peshawar. The Khyber Agency is home to Lashkar-e-Islami, a militant organization sometimes allied with the Pakistani Taliban. Discussing the conclusions of the latest review of the Afghan war strategy, Obama administration officials said this week that the United States would be more aggressive in going after militants in the tribal areas â€” with or without Pakistanâ€™s help.