Then in May last year a special forces raid in Helmand killed the next most important associate of Mullah Omar and the Taliban's alleged chief strategist, Mullah Dadullah. A Kakar tribesman who lost a leg in combat, Dadullah became known as the "al Zarqawi of Afghanistan" after ruthless execution of hostages and ex-spies. He was credited with the introduction of suicide bombers into the country. Dadullah's body was displayed to reporters by the Governor of Kandahar.
Though split into many small factions, the Taliban movement in the south seemed to be split broadly into two factions. One, consisting of more local tribal factions, reported to Mullah Abdul Rahim and then to Mullah Omar; and the other more extreme one, with closer links to Al Qaeda and more foreign fighters, who took orders from Mullah Dadullah.
Strikes on lower level leadership continued throughout year and culminated last November and December in strikes on the Taliban's then stronghold of Musa Qala in northern Helmand.
By then Dadullah's faction had been taken over by his brother, Mansour Dadullah. But after a split with Mullah Omar, Dadullah was captured in late December by Pakistan forces. Afghan intelligence reports have suggested he may later have been released in exchange for the Pakistan ambassador who had been taken hostage, but one source said there were no indications he continued to play any current role.
This summer, strikes on the Taliban leadership included the elimination by air strike of what the Afghan Army claimed was the Taliban's entire leadership council for Kandahar province, including Mullah Abdul Shukur, the Taliban governor of Kandahar; Mullah Kamran, the chief of police and Mullah Baaz Mohammad, chief of intelligence for the province.
Meanwhile in Helmand, late June saw the death of what NATO declared as a "planner and bomb-maker", Mullah Sadiqullah, and a key strategist named Mullah Bishmullah on July 12. Then just after midnight on Sunday, a day after Abdul Rahim's capture, a missile strike from a British aircraft killed Abdul Rasaq, a Taliban leader who led fighters in the Musa Qala area of Helmand province, according to a British spokesman who spoke to the Associated Press. Rasaq was also known as Mullah Rahim.
But whatever the success against the leadership down South, the Taliban movement remains a potent threat to American and British forces, with most Afghans reporting that security continues to be on the slide.
Stephen Grey is the author of "Ghost Plane: The True Story of the CIA's Rendition and Torture Program" (St Martin's Press). He is an award-winning investigative reporter who has contributed to the New York Times, BBC, PBS and ABC News among others.