Mr. Panetta scuttled the program, which would have relied on paramilitary teams, shortly after the C.I.A.’s counterterrorism center recently informed him of its existence. The next day, June 24, he told Congressional Intelligence Committees that the plan had been hidden from lawmakers, initially at the instruction of former Vice President Dick Cheney.

The program was designed in the frantic weeks after the Sept. 11 attacks when President George W. Bush signed a secret order authorizing the C.I.A. to capture or kill operatives of Al Qaeda around the world. To be able to kill Osama bin Laden or his top deputies wherever they might be  even in cities or countries far from a war zone  struck top agency officials as an urgent goal, according to people involved in the discussions.

But in practice, creating and training the teams proved difficult.

“It sounds great in the movies, but when you try to do, it it’s not that easy,” said one former intelligence official. “Where do you base them? What do they look like? Are they going to be sitting around at headquarters on 24-hour alert waiting to be called?”

A C.I.A. spokesman declined to comment for this article.

There has been intense speculation about the nature of the program since members of the House Intelligence Committee disclosed last week that Mr. Panetta had put an end to it. The Wall Street Journal reported on Monday that the secret program was intended to capture or kill senior Qaeda leaders.

Current and former officials said that the program was designed as a more “surgical” solution to eliminating terrorists than missile strikes with armed Predator drones, which cannot be used in cities and have occasionally resulted in dozens of civilian casualties.