"high value" detainees are those who knew the most about AQ's support network and global patrons. It seems obvious that if the real object of these operations was to shut down the financial and support network that makes terrorist operations possible, the US would go out of its way to capture alive for interrogation those who know the most about these details.
Managers of the program would also make damn sure that the methods used to capture and interrogate such detainees did not damage their ability to accurately recall details. Under this criteria, waterboarding (partial drowning which kills brain cells) is obviously out, as is prolonged sleep deprivation (which can also result in memory impairment). Yet, the approach actually taken to these major AQ figures has been the one that quite predictably yields the least accurate information or destroys the evidence. See,
http://www.dailykos.com/story/2009/09/22/785150/-AP:-CIA-Torture-Damaged-Brains,-Recall-of-9-11-SuspectsIt's not like I'm the only one who has said this about the efficacy of certain types of "enhanced interrogation techniques." The FBI also objected to waterboarding and psychological torture of AQ detainees for the same reason.
The unanswered question is: why kill the most important witnesses and destroy the evidence, when there is a choice? See,
http://journals.democraticunderground.com/leveymg/334As for al-Awlaki, he has had the most remarkable history of being the hub or connecting spoke in the wheels of AQ operations and miraculously being subsequently let go by the authorities or sidestepping the bullet. He's facilitated more actual and attempted terrorist attacks on American targets than anyone else, going back to his role as "spiritual advisor" for the Flt. 77 hijackers, overseeing them in San Diego and then traveling cross-country to join them in the DC area in the months before 9/11. He's like a lightening rod for terrorists - they always manage to find him, and vis-a-versa. Given his apparent usefulness, I am not surprised that he continually gets "thrown back" and escapes attempts to kill him. Please, see, related,
http://www.dailykos.com/story/2011/02/02/940661/-Wikileaks-reveals-9-11-Team-Bhijack-team-got-away