For all the talk in Washington of waging "war" on terrorism, the biggest impact in thwarting future attacks against the United States may not come from cruise missiles or ground troops scouring Pleistocene caves for Osama bin Laden. It will come from the "secret war" - human intelligence gathering.
Already, a push is under way to "unshackle" the CIA - allowing it to engage in assassinations, hire "unsavory" agents, and do whatever else it can to infiltrate Islamic extremist groups.
But behind the move to revamp the nation's intelligence-gathering operations lie a host of practical problems that will make any secret war difficult to win, or even to begin.
Beyond the moral questions raised by any change in tactics, the CIA will have to undergo a fundamental shift in culture and mission. Indeed, the nation's intelligence apparatus, much of it created in the cold-war era, is facing a distinctly different task from what it was built for - a world with one clear enemy.
For one thing, questions exist over whether US intelligence has the right tools in its box for the job and how quickly it can get them in place. The hunt for bin Laden will undoubtedly require help from friends in the region, experts say. But the bigger mission, a war on terrorism, is going to require a new idea of how intelligence works.
"People are looking for easy answers," says Loch Johnson, a University of Georgia professor and author of "Secret Agencies: US Intelligence in a Hostile World." "They want to think, 'If only we unleash the CIA or allow assassinations,' but as always the truth is more complicated."
The CIA's foreign officers are not the James Bonds or even the Rambos that some people may believe they are. They are largely white-collar bureaucrats, many of whom who have embassy cover jobs and are usually not terribly immersed in the culture they are living in, says Reuel Marc Gerecht, a former CIA officer in the Middle East who quit the agency out of frustration.
Such officers recruit foreign nationals to do the actual spying, and not even they are called upon to undertake dangerous action missions. They are information gatherers, in part because taking action would threaten their anonymity and safety, thereby risking the very intelligence-gathering capability they were recruited to provide.
To expect CIA officers to shift suddenly into a search-and-capture, or even kill, mode is unrealistic. More likely, host nations' security forces would be enlisted to capture terrorists fingered by the US. "That's why it is so important for us to build a consensus on this around the world," says Norb Garrett, a former senior operations officer with the CIA and president of business intelligence at Kroll Associates. "We need friends. We can't do it alone."
But those friends may be difficult to come by, says Mr. Gerecht. By opening relations with Pakistan, it is possible the US will find that officers from that country's Inter Service Intelligence (ISI) will "walk-in" with good information on bin Laden, but such liaison operations are always complicated.
"I would imagine there will be a lot of walk-ins in the next few weeks, and some may be good," Gerecht says, but adds: "Are there a lot of friends of the US in the ISI? Sure. Are there a lot of enemies? Sure. Can you compartmentalize them? Who knows."
Of course, building those relationships and others goes back to the talk that has been bandied about Washington this week concerning the hiring of "unsavory types" and permitting assassinations. But many experts say that while talk like that is nice for policy mavens, those restrictions have never carried much weight out in the field.
Assassination essentially gets down to how one defines the term. If, indeed, the intelligence services knew for certain where bin Laden was, a cruise missile attack would likely be the choice of attack rather than a stiletto. And the hiring of agents or informants with shady backgrounds isn't the red flag people believe.
"I don't know of a single case officer anywhere who has ever had that concern," Gerecht says. "If they could get someone reliable in a terrorist cell working for them, they'd happily take it."
Currently, much of the CIA "recruiting" operations, such as they are, take place on what one might call the cocktail circuit. Officers meet people in other countries in similar positions to them, often white-collar business types, some of whom work at embassies.
They try to identify who might make a good "target" for recruiting. But even then the process takes time, the targets must be developed, and the information they receive must be vetted.
"The reality is that most of the recruiting is pretty worthless," Gerecht says. "The best agents are always walk-ins."
Indeed, FBI turncoat Robert Hanssen was not recruited by Russian intelligence, but instigated the relationship himself.
The larger changes for US intelligence, however, may be even more difficult to bring about. It is, in the end, a question of changing a bureaucracy.
Indeed, some say the CIA's mission, to centralize intelligence operations that before were spread out among many different components of government, has itself become outmoded.
They argue that while the agency clings to a 1980s-style centralized management structure, prevailing theory holds that the most effective approach is small, nimble, decentralized units - curiously like the cells of terrorist organizations.
"[The CIA] is still organizing, for better or worse, along geographic lines," says Garrett. "Terrorism is a bigger target than the Near East Division, but it still falls under the leadership of that division, which looks at terrorism as being only a part of their authority."
Others doubt anything of substance can be done quickly to improve the CIA's terrorism-fighting capability. They say that while fundamental change could be expected to take years to accomplish, even something as basic as placing more Arabic-speaking intelligence officers in the field is hampered by the typical two-year learning curve for the language.
And even though a cultural shift may be needed in American intelligence, they stress that such changes will not mean America's "war on terrorism" will be won.