The United States was struggling yesterday to contain the latest crisis in relations with Pakistan triggered by the killing on Saturday of 24 Pakistani soldiers in an apparent Nato airstrike at an outpost on the border with Afghanistan.
As Pakistan blocked key Nato supply routes and some Afghan officials pointed the finger of blame across the border, Hillary Clinton, the Secretary of State, was among US officials calling counterparts in Islamabad to express regret and try and patch up already deeply damaged relations.
The Nato Secretary General, Anders Fogh Rasmussen, supported an investigation launched by ISAF, the Nato-led international force in Afghanistan.
However, Pakistan's Foreign Minister, Hina Rabbani Khar, told Ms Clinton yesterday that the strike negated all progress in improving the strained alliance between the two countries and confirmed that in response Pakistan had closed two border crossings used by Nato to supply forces in Afghanistan, and expected the US to vacate an airbase used to back up drone operations.
Those actions fuelled distrust and irritation with Pakistan on Capitol Hill. Senator Dick Durbin, the number two Democrat in the Senate, said American troops were coping with problems that include "the incompetence and maybe corruption in Afghanistan and the complicity in parts of Pakistan". Senator John Kyl, a Republican, said the US needs to engage in some "tough diplomacy" with Pakistan.
Brigadier General Carsten Jacobson, spokesman for the ISAF, said it was "highly likely" that Nato helicopters had caused the deaths on Saturday of the Pakistani soldiers. "There was an operation on the ground in Kunar conducted by a combined Afghan and American force. A tactical situation developed on the ground resulting in an airstrike being called in."
With a border that is rugged and largely unmarked, the risk of fire being misdirected by accident is always present. A number of Afghan officials claimed that the firing started from the Pakistani base, and that the Nato helicopter was responding to an attack on its troops. The Afghan ministries of defence and interior would not comment.
However, there was widespread rage across Pakistan yesterday where sentiments towards the US have darkened since the raid that killed Osama bin Laden in a Pakistani garrison town, planned and carried out without the knowledge of Pakistan's leaders.
An angry crowd of at least a thousand people was gathered through most of yesterday outside the US consulate in Karachi. Much of the nation was gripped by live television coverage of the funerals of the soldiers killed in the strike. Lorries filled with supplies for Nato troops were already backed up at the two border crossings closed down by the government at Torkham and Chaman. The US has two weeks to leave the Shamsi airbase, which is used for drone operations.
"Pakistan announced it was closing lines of communication across the border," General Jacobsen said. "This is not a problem for us in an operational sense, but it is in all our interests to get back to normal as soon as possible. It is in all our interests – Pakistan, Afghanistan, the international community – to return to normal because the only people who are profiting from this are Taliban insurgents."
In Washington, a spokesman for the National Security Council, Tommy Vietor, confirmed that "senior US civilian and military officials have been in touch with their Pakistani counterparts from Islamabad, Kabul and Washington to express our condolences, our desire to work together to determine what took place, and our commitment to the US-Pakistan partnership which advances our shared interests, including fighting terrorism in the region".
Timeline: souring of relations
27 January, 2011
Raymond Davis, a CIA agent, allegedly shot dead two Pakistanis who were tailing him in Lahore. With the US claiming he had diplomatic immunity, the incident led to a major diplomatic furore.
2 May, 2011
Al-Qai'da leader Osama bin Laden is killed in a unilateral Navy Seals raid in the Pakistani city of Abbottabad. US officials said Pakistan was not informed due to concerns that it may have alerted the target.
13 September, 2011
An attack on several buildings in Kabul, including the US embassy, kills 25 people. America's most senior military officer, Admiral Mike Mullen, describes the group behind the attack, the Haqqani network, as "a veritable arm" of Pakistan's spy agency.