The important strategic relationship between the United States and Pakistan is under review after the killing of 24 Pakistani soldiers by US armed forces this weekend. Nato forces attacked two Pakistani border posts on Saturday in an unprovoked assault. Both Nato and the United States have apologised for the attack, but that will not repair the damage.

In 2001 after the terrorist attacks in New York and Washington, Pakistan's military government of Pervez Musharraf was given an ultimatum from US President George W. Bush who made clear that "you are either with us or against us". Despite this graceless American ultimatum, Pakistan has worked hard to contain terrorist forces, going well beyond the minimum required with substantial costs involved, and many soldiers killed.

Nonetheless, Pakistan is well aware that it will have strategic interests in Afghanistan long after Nato leaves, which will happen in the foreseeable future. President Asif Ali Zardari and Prime Minister Yousuf Raza Gilani will need to balance their present alliance with the US with the knowledge that the US will not be around in the region for very long. They will also need to recognise the deep anti-American feeling in Pakistan, fuelled by continual killings of civilians by drones, and regular incursions into Pakistani territory.

When a similar incident in 2010 resulted in the death of two Pakistani soldiers, Pakistan closed the supply routes to Nato forces for 10 days. But the latest tragedy comes at a more decisive moment, as the region is preparing for a Nato retreat from Afghanistan. Too much is at stake for Pakistan to cut ties completely with the US, but the temptation to do so must be very strong. Washington needs to do more to reassure its ally, Pakistan, that it is worth remaining friends.