It is exactly 12 years since the US went to war in Afghanistan, engineered the downfall of the Taliban and brought a civilian government under Hamid Karzai to power.
But the relationship has never been easy, and it reached another low point last week in a public spat between Leon Panetta, the US defence secretary, and Karzai. Panetta said the Afghan president should be expressing gratitude, not complaint.
"[Panetta] is voicing a sentiment that I hear quite common inside of the US government, a sense of frustration about the, at times, lack of appreciation for how much US troops and US taxpayers have committed to Afghanistan, despite tactical errors and other things."
- Brian Katulis, a senior fellow at the Centre for American Progress
This came after Karzai accused the US of ignoring what he sees as a basic fact – that the roots of the ongoing insurgency in Afghanistan lie in neighbouring Pakistan.
"America and Afghanistan should fight this war where terrorism stems from. But the United States is not ready to go and fight the terrorists there. This shows the double standards. They say one thing and do something else," said Karzai.
The Afghan president says the US has failed to give his forces weapons, and threatened to turn to Russia and China for arms.
In response Panetta said: "We've lost over 2,000 men and women, ISAF has lost forces there and the Afghans have lost a large number of their forces in battle. Those lives were lost fighting the right enemy, not the wrong enemy.
"I think it would be helpful if the President [Karzai] every once in a while expressed his thanks for the sacrifices that have been made by those who have fought and died for Afghanistan, rather than criticising."
"The whole term of the terrain being harsh is, frankly put, a smokescreen because a lot of militant networks are operating in urban areas in Pakistan … We have to be careful with focusing too much on this idea that the border lands are either tribal or harsh terrain and that's why they are a source of problems."
- Haseeb Humayoon, a political analyst and partner at Qara Consulting Inc
The statements come amid growing tensions between the two countries.
Relations have been made worse by the killing of civilians which Washington insists are accidental; by the US military's refusal to release a number of prisoners to Afghan control; and by the so-called 'green on blue' killings, or "inside attacks".
At least 51 members of the western coalition forces have been killed by uniformed Afghan troops or police in the past year.
The US is scheduled to withdraw all combat troops from Afghanistan by 2014.
So how deep is the tension between the US and Afghanistan? And will it affect the US withdrawal?
Joining the discussion on Inside Story with presenter Mike Hanna are guests: Haseeb Humayoon, a political analyst and a partner at Qara Consulting Inc, a Kabul-based policy advisory firm; Brian Katulis, a senior fellow at the Centre for American Progress who specialises in US national security in the Middle East and South Asia; and Sohail Mahmood, a political analyst and author of numerous reports on foreign policy in the Middle East and South Asia.
"The [Afghan-Pakistan] border is porous for a reason. The terrain is such that no power on earth can stop infiltration from either side. Yes infiltration is happening on both sides [and] a double game is also being played by the US."
Sohail Mahmood, a South Asia and Middle East specialist
Source of Afghanistan-Pakistan tensions:
- The border has been a source of tension between the two countries for many years
- Called the Durand Line it was a boundary unilaterally established by the occupying British in 1893
- The Durand Line sliced through the Pashtun tribal areas that still straddle the now-sovereign states of Afghanistan and Pakistan
- It was a border that simply ignored the tribal allegiances of those who lived on both sides of it
- Afghanistan and Pakistan each accuse the other of stirring tension along this grey area that supposedly marks the territory of sovereign nations
- Each state insists that the other is providing safe havens for fighters to launch attacks across this porous line of national demarcation