Karen DeYoung

and Joshua Partlow

The latest U.S.-Pakistan crisis continued Tuesday to threaten the Obama administration’s strategy for gradually ending the war in Afghanistan, as the Islamabad government said it would boycott an upcoming international conference in Germany on Afghanistan’s future.

The Pakistani cabinet, after a meeting in the eastern city of Lahore, said in a statement that it supports “stability and peace in Afghanistan and the importance of an Afghan-led, Afghan-owned process of reconciliation and expressed the hope that the international community will reaffirm its support for peace and development in Afghanistan at the forthcoming Bonn Conference.”

But Pakistan, it said, had decided to bow out “in view of the developments and prevailing circumstances.”

The decision came despite pleas from Afghan President Hamid Karzai to Pakistani Prime Minister Yousuf Raza Gilani. According to an account provided by Gilani’s office, Karzai called Gilani and argued that a boycott of the conference, scheduled for Dec. 5, would not encourage peace in Afghanistan.

Gilani responded: “How could a country whose own sovereignty and territorial integrity was violated from the Afghan soil . . . play a constructive role?”

One Western official who spoke on the condition of anonymity called the boycott “very unfortunate,” adding, “Pakistan is taking itself from the table precisely when it should be contributing to a solution in Afghanistan.” Pakistan’s participation, and its cooperation in the winding-down of the war in Afghanistan, is important in large part because of the leverage it is believed to have over the Taliban.

The move to shun the conference was made as two senior Pakistani military officers briefed local editors and commentators on the cross-border U.S. airstrike that killed at least 24 Pakistani soldiers early Saturday. The officers reiterated Islamabad’s contention that coalition forces had ignored appeals by Pakistan for NATO helicopters to stop firing on its checkposts.

All Pakistani soldiers at the post, as well as the reinforcements sent to assist them, were uniformed, Maj. Gen. Ashfaq Nadeem, the director general of military operations, told reporters.

“All coordination procedures were violated,” he said. “At multiple levels in ISAF, it was known that they were attacking Pakistani posts, but they continued with impunity,” Nadeem said, according to one television network editor who was present.

Nadeem said the Pakistani military had concluded that the strike was an “attack of blatant aggression.”

That assessment appeared to be becoming more widespread Tuesday in Pakistan, where newspaper editorials and street protesters, including members of an association of Pakistani truckers who carry supplies to NATO troops in Afghanistan, called for the nation to end its alliance with the United States.

In Lahore, the top official of the opposition-led province of Punjab, Shahbaz Sharif, met with the wife of one of the soldiers killed in the airstrike. According to a statement from Sharif’s office, the widow, “despite being in a deep state of grief and sorrow, said, ‘Those we are fighting for are not our friends.’ ”

Obama administration officials did not respond Monday to Pakistani demands for an apology for the strike. Instead, they expressed condolences for the loss of life while saying that the facts about what happened were under investigation.

Both sides have said they believed they were attacking insurgents along the border Saturday when the strike was launched. A senior Pakistani defense official acknowledged Monday that Pakistani troops fired first, sending a flare, followed by mortar and machine-gun fire, toward what he said was “suspicious activity” in the brush-covered area below their high-altitude outpost barely 500 yards from the border.

According to Afghan security officials, their commandos were engaged with U.S. Special Operations troops in a nighttime raid against suspected Taliban insurgents when they came under cross-border fire and called in an airstrike.

Despite extensive coordination mechanisms set up to prevent such encounters, the U.S. military failed to respond to Pakistani alerts that its troops were being bombed, said the Pakistani defense official, who spoke on the condition of anonymity because he was not authorized to discuss the issue on the record.

“We told them, hold your horses, these are ours,” the official said. While repeated urgent appeals went up the coalition chain of command, he said, the airstrike continued for an hour and a half against two Pakistani border positions and a contingent of troops.

Administration and U.S. defense officials raised the possibility of a different set of circumstances but declined to elaborate.

“Where we are is that we’ve regretted the loss of life and said there should be an investigation,” said a U.S. official who agreed to speak about the tense situation only on the condition of anonymity. “We've just got to put one foot in front of the other here.”

The Pentagon placed the U.S. Central Command in charge of the inquiry, and Centcom’s commander, Gen. James N. Mattis, announced Monday that a Special Operations officer would head it. Air Force Brig. Gen. Stephen Clark was directed to include representatives of NATO and the Pakistani and Afghan governments on the investigation team and to report his conclusions by Dec. 23.

Pakistani anger rising

The investigation, however, risked being overtaken by events in Pakistan, where the government and military commanders are under strong pressure from the increasingly anti-American Pakistani public and the ranks of the army to end counterterrorism cooperation with the United States.

“You cannot win any war without the support of the masses,” Gilani told CNN. “We need the people with us.” Gilani said that “business as usual” with the United States could not continue.

Pakistan has blocked NATO supplies transiting to Afghanistan at two border crossings and threatened to withdraw from an international conference on Afghanistan next week in Germany. A small contingent of U.S. personnel at Shamsi air base in southern Pakistan was told to leave within 15 days.

Relations were already fractured after a series of clashes this year, including the January shooting death of two Pakistanis in Lahore by a CIA contractor, the U.S. raid that killed Osama bin Laden in Pakistan in May and public U.S. charges that Pakistan’s intelligence service has aided Afghan insurgent networks within its borders.

“You crawl back” from those incidents, the U.S. official said, “and then there is this. There is no question, this is the worst.”

The administration views Pakistani cooperation as crucial to its hopes of bringing Afghan insurgents to the negotiating table within the next year and developing a regional trade zone that could ultimately allow Afghanistan’s economy to prosper without massive foreign aid.

“This imperfect partnership is no longer enough to save Afghanistan,” said Moeed Yusuf, South Asia adviser at the U.S. Institute of Peace. He said President Obama’s plans to withdraw nearly 100,000 combat troops between next month and the end of 2014 require “an almost perfect coordination effort” with other elements of the administration’s strategy.

“I just don’t see how this is going to happen,” Yusuf said.

Conflicting accounts

Secretary of State Hillary Rodham Clinton and Defense Secretary Leon E. Panetta issued a joint statement of condolence over the deaths, and CIA Director David H. Petraeus telephoned his Pakistani counterpart Sunday. “Our side says they don’t know the facts,” said a second U.S. official, who also declined to discuss the matter on the record. “The facts are undoubtedly that somebody messed up on both sides.”

A former U.S. official who closely follows events in the region said the Pakistani army’s 11th Corps command near the western border was informed that coalition operations would take place Friday night and Saturday morning in the Maya area of Afghanistan’s Konar province. Maj. Gen. Athar Abbas, the chief Pakistani military spokesman, said in an interview Sunday that coalition forces “informed our military earlier, much earlier, that they will be conducting an operation there.”

Afghan security officials said Monday that the Special Operations mission was targeting training bases and hideouts of Taliban fighters. Insurgents there had regularly fired at a U.S. base in the area in the past, the officials said.

The Afghan officials said the coalition troops came under fire from the vicinity of the Pakistani bases, located in the Mohmand tribal areas, and they called in airstrikes in self-defense.

One senior Afghan police official said that after an initial gun battle, the insurgents retreated into a Pakistani post and began firing from there. “They started firing at the commandos, and they continued firing, so the air support had to come to their defense,” the official said.

The Pakistani defense official offered a sequence of events that differed in key aspects.

The Pakistani post, called Volcano, is clearly marked on grids shared with Afghan and coalition forces and flies the Pakistani flag. Its mission, the official said, is to prevent the return of Afghan insurgents that Pakistan has driven over the border. “We have repeatedly sensitized our friends [in Afghanistan] to this situation and asked their cooperation,” the official said.

Early Saturday, he said, Volcano “detected suspicious activity — sound and movement — in the vicinity. They are sitting there for the express purpose of stopping infiltration, so what do they do? They fire a few flares, a couple of mortar rounds and one or two bursts of heavy machine-gun fire in that direction.”

The Pakistani official added that “there was no return fire” from the ground. He dismissed suggestions by U.S. officials that the subsequent strike on Volcano and another post by U.S. attack helicopters and helicopter gunships was a case of mistaken identity provoked by Taliban forces in the area.

Even if the attack began that way, he said, “within a maximum of 10 or 15 minutes” the Americans should have known they were Pakistani military posts.

DeYoung reported from Washington and Partlow from Kabul. Special correspondents Sayed Salahuddin and Javed Hamdard in Kabul, Shaiq Hussain in Islamabad and Haq Nawaz Khan in Peshawar contributed to this report.