The 33,000 additional US troops that President Barack Obama ordered to Afghanistan to stamp out the Taliban attacks nearly two years ago have now left the country, but a new wave of deadly insider attacks and a reassessment of how Nato troops partner with Afghans have raised questions about how well the military strategy is working.
US defence secretary Leon Panetta announced the troops had come out, declaring the surge had accomplished its mission.
But after a tumultuous week in Afghanistan that saw commanders put limits on when Nato and Afghan troops can patrol together, Panetta also acknowledged there will still be difficult days ahead.
"The surge did accomplish its objectives of reversing the Taliban momentum on the battlefield and dramatically increasing the size and capability of the Afghan national security forces," Mr Panetta told reporters at a press conference at Government House in Auckland where he was meeting New Zealand leaders.
He said the re-deployment of the 33,000 troops was a "very important milestone" and that the US is on track to accomplish its goals in Afghanistan. The withdrawal, which was completed on schedule, still leaves close to 100,000 Nato troops there, including 68,000 Americans.
Panetta's success mantra, however, is called into question by the decision earlier this week that, at least temporarily, Nato operations with small-sized Afghan units are no longer routine, and will require the approval of the regional commander.
Until now, coalition troops routinely conducted operations such as patrolling or manning outposts with small units of their Afghan counterparts. But a growing wave of so-called insider attacks in which Afghan Army and police troops, or insurgents dressed in their uniforms, have been turning their guns on US and Nato forces, has shaken the trust between the allied troops and the Afghans they are there to train.
And it has called into question the core strategy that relies on Nato troops working shoulder to shoulder with Afghans, training them to take over the security of their own country so the US and its allies can leave at the end of 2014 as planned. As of this week 51 coalition troops have been killed in such attacks this year.
Australian Brigadier General Roger Noble, deputy to the alliance's operations chief, acknowledged earlier this week that the attacks are rattling the troops.
"It strikes right at the heart of our resolve," he said. "It's one thing to be killed in action by the insurgents. It's quite another to be shot in the back of the head at night by your friends."