All the apologies in the world aren't going to mend this friendship.
When your ally is flying drone attacks on your territory or, seen from the other point of view, is sheltering your worst enemies, it is safe to say that the relationship needs to be re-evaluated. The latest shots fired in the uneasy alliance between the United States and Pakistan have resulted in 50 Nato fuel trucks burnt and a blockade of vital supply lines for the Afghan war. That, in turn, was triggered when Nato helicopters crossed the border and killed several Pakistani soldiers.
American and Nato officials, most recently the US ambassador Anne Patterson, have fallen over themselves apologising, but in truth the sortie was not all that unusual. Nato says the gunships were fired upon first and followed hostiles across the porous border.
Besides, the United States has been operating a punishing drone campaign in Pakistan's tribal areas for the last six years. Despite the humble words from Washington, there is every sign that campaign will intensify. After hostility towards the US briefly abated because of flood-relief efforts, the undeclared war on Pakistani soil has re-ignited the fires.
There is duplicity on both sides. Elements of the Pakistani government, military and, especially, intelligence services are not only shying away from confronting Taliban factions based in the tribal areas - which, arguably, might be in their long-term interest - but funding and organising the insurgency in Afghanistan.
It was not surprising that Taliban attacks on the fuel convoys followed so soon after Islamabad blocked supply lines. It did, however, reveal how vulnerable the Afghan war effort is. If Pakistan decides to turn off the flow of fuel and supplies to Nato forces, they will be hamstrung.
The Obama administration has difficult decisions to make. The drone attacks have their logic: they have proven an effective tool of assassination against militants that Pakistan won't fight.
In the last week, drones have killed Germans suspected of plotting European terrorist attacks and a Briton with a direct link to the failed Times Square bombing. But attrition isn't a winning strategy in this war. In the long term, relations with Pakistan are more important than simply killing militants.