Washington:
When Pakistani security officers raided a house outside Karachi in late January, they had no idea that they had just made their most important capture in years.
U.S. intelligence agencies had intercepted communications saying militants with a possible link to the Taliban's top military commander, Mullah Abdul Ghani Baradar, were meeting. Tipped off by the Americans, Pakistani counterterrorist officers took several men into custody, meeting no resistance.
Only after a careful process of identification did Pakistani and U.S. officials realize they had captured Baradar himself, the man who has long overseen the Taliban insurgency against U.S., NATO and Afghan troops in Afghanistan.
New details of the raid indicate that the arrest of the No. 2 Taliban leader was not necessarily the result of a new determination by Pakistan to go after the Taliban, or a bid to improve its strategic position in the region. Rather, it may be something more prosaic: "a lucky accident," as one U.S. official called it. "No one knew what they were getting," he said.
Relations between the intelligence services of the United States and Pakistan have long been marred by mutual suspicions that Pakistan has sheltered the Afghan Taliban. The Pakistanis have long denied it.
Baradar's capture was followed by the arrests of two Taliban "shadow governors" elsewhere in Pakistan. While the arrests showed a degree of Pakistani cooperation, they also demonstrated how the Taliban leadership has depended on Pakistan as a rear base.
Jostling over the prize began as soon as Baradar was identified. Officials with the Directorate for Inter-Services Intelligence, Pakistan's military spy agency, limited American access to Baradar, not permitting direct questioning by CIA officers until about two weeks after the raid, according to U.S. officials who discussed the issue on condition of anonymity.
"The Pakistanis are an independent partner, and sometimes they show it," said one U.S. official briefed on the matter. "We don't always love what they do, but if it weren't for them, Mullah Baradar and a lot of other terrorists would still be walking around killing people."
"The Pakistanis have a delicate problem with Baradar," said Bruce Riedel, an expert on Afghanistan at the Brookings Institution, who advised the Obama administration on Afghan policy early last year. "If I were in their shoes, I'd be worried that he might reveal something embarrassing about relations between the Afghan Taliban and the Pakistani government or Inter-Services Intelligence."
A Pakistani official expressed impatience with questions about past conflicts over the Afghan Taliban, saying, "It's high time now that we move beyond that."
Baradar is talking a little, though he is viewed as a formidable, hard-line opponent whose interrogation will be a long-term effort, according to U.S. and Pakistani officials.
Despite the tensions, interviews with Pakistani military and intelligence officials suggested that the Taliban leader's capture could alter Pakistan's calculus about the volatile region.
Taking him off the battlefield, and exploiting the information he might provide, could deal a blow to the Taliban's military capability. In the long run, in any discussions of the future governance of Afghanistan, Baradar could become a bargaining chip and, conceivably, a negotiator.
In interviews on Thursday, Pakistani officials said an aggressive strategy to weaken the Taliban's leadership might cripple the movement enough to bring it to the negotiating table.
"Maybe Mullah Baradar's capture gives us a breakthrough in terms of reconciliation," said one Pakistani intelligence official in Islamabad, Pakistan's capital, who spoke on condition that he not be named. But the official said such a strategy ran the risk of making the Taliban "more hostile" or possibly of giving a Taliban hard-liner too much influence in negotiations.
Riedel, of the Brookings Institution, said the tensions surrounding Baradar were inevitable, but minor compared with the value of removing him from the battlefield. He said Pakistan's cooperation could be a sign that official attitudes there, which have favored the Afghan Taliban while condemning the Pakistani Taliban, are changing.
"I believe the Pakistanis have finally concluded that the Afghan Taliban and Pakistan Taliban were cooperating against them in Waziristan and elsewhere," Riedel said, referring to links among various militant groups in Pakistan's tribal areas.
An Obama administration official sounded a more cautious note about the recent arrests. "All this is not necessarily related to a rational decision at the top of the Pakistani military to see things our way," the official said. "I don't see any big shift yet."
The likely impact of Baradar's detention on prospects for talks with the Taliban, which have been the subject of intense speculation in recent months, is in dispute.
Alex Strick van Linschoten, a Dutch researcher who has lived for several years in Kandahar in southern Afghanistan, said Taliban representatives reacted with fury to Baradar's arrest and were unlikely to be amenable to political approaches any time soon.
"This ends all that," said Strick van Linschoten, who helped a former Taliban official, Abdul Salam Zaeef, write a memoir published last month in English, "My Life with the Taliban."
Strick van Linschoten said the killing and detention of an older generation of Taliban, including Mullah Baradar, who fought Soviet troops in the 1980s, may leave a younger, decentralized force of militants who are less interested in and less able to conduct negotiations.
"On a local level in Afghanistan, Taliban fighters operate fairly independently," he said. "They're self-sustaining, by taxing the drug trade or taxing construction projects, and they'll just keep fighting."
Baradar, who is in his early 40s and is said by most officials to belong to the same Popalzai tribe as President Hamid Karzai of Afghanistan, is believed to be one of a handful of Taliban leaders in periodic contact with Mullah Muhammad Omar, the reclusive, one-eyed founder of the Taliban.
Their leadership council is known as the Quetta shura, and they are believed to have operated around the Pakistani city of Quetta since the Taliban government in Kabul, the Afghan capital, fell in 2001. But Strick van Linschoten said he heard in Kandahar that Taliban leaders were feeling increasingly vulnerable in Quetta.
As a result, Afghan Taliban leaders are believed to have been spending more time in Karachi, Pakistan, a sprawling port city of more than 15 million, where they believed that they would be harder to find.