The metrics of that success, perhaps unsurprisingly, have concentrated on the lethality of US and Nato operations.
From April to July this year – according to a briefing given to the Associated Press – 2,832 special forces raids have led to the deaths of 834 insurgents, while another 2,941 have been captured.
Because of this, according to Petraeus himself, violent attacks have fallen by 14% in 12 months.
"The [Taliban] have less capacity, they have been degraded somewhat," he told the New York Times. "This is the first real indicator – for the first time since 2006 – compared with the previous year, insurgent attack numbers are lower."
These would be impressive figures and claims except for one problem: the US military's figures are starkly contradicted by other sources.
For even as Petraeus was busy talking up his success earlier this month, the UN mission in Afghanistan was describing the course of the conflict in far more bleak and bloody terms.
Speaking on 14 July, Stefan de Mistura, special representative of the UN secretary general for Afghanistan, and his colleague Georgette Gagnon – director of human rights for the mission – described a 15% increase in civilian casualties in the preceding six months, with May 2011 the deadliest month of the war for civilians since 2007.
According to Gagnon (pdf): "The human cost of the Afghan conflict for Afghan civilians rose in the first six months of 2011.
"Afghan civilians experienced a 15% increase in conflict-related civilian deaths over the past six months compared with the same period in 2010."