After his confirmation hearing in 2013, CIA Director John Brennan and other senior managers explained that the Agency would be seeking to enhance its ability to spy using human agents. It was an admission that to a large extent the United States intelligence community had forgotten how to engage in what was once a core capability that had defined its clandestine services for nearly seventy years. Now the Pentagon, which always favored technical spying over its HUMINT efforts because human spies are both unpredictable and considerably prone to embarrassing incidents, is essentially saying the same thing. Everyone is trying to revive the old-time tradecraft in part because machines have failed to collect the right kind of intelligence at the times when it is needed.

Secretary of Defense Ash Carter testified before the House Armed Services Committee on December 1 that a new formation of special operations soldiers tasked, among other things, with “dramatically accelerating the collection of intelligence” would be fielded in Iraq. The unit would most likely be based in or near Irbil, a Kurdish region and therefore a safe destination for U.S. forces. It will likely work together with Kurdish militiamen though it will also be operating unilaterally without coordination with the Iraqi military intelligence services, considered to be both unreliable and possibly even subversive due to reported penetration by the Iranian Revolutionary Guards.

This development means that American soldiers will be actively engaged in combat operations in both Iraq and Syria without the consent of any national government. It raises some significant legal issues and perhaps even threatens the security of other U.S. troops that are advising the Iraqi Army, particularly if there is an incident in which civilians are killed.

The U.S. troops are not yet in place and even the numbers that will be involved are unclear, though Pentagon insiders guess that they will be in the low hundreds and may even be drawn from or replace some of the estimated 3,300 U.S. soldiers currently in Iraq.

An important distinction being drawn by the Pentagon is that the new soldiers will not be limited to advisory roles and will instead be allowed to actively engage the enemy. They are expected to conduct raids, free hostages and capture ISIS leaders in addition to collecting intelligence. It is to be presumed that rules of engagement they will be operating under would allow them to kill ISIS leaders if capture is not feasible, as was alleged to be the case with Osama bin Laden.

There have been reports that some of the 300 advisers sent to Iraq in June 2014, which was followed by an additional 50 special ops soldiers in December ordered to “advise, train and assist,” have already been exceeding their mandates by directly participating in fighting between local militiamen and ISIS. This has been denied by the Pentagon even though Kurdish officers have confirmed their presence with cell phone photos.

Other U.S. special forces units have been involved in separate raids on targets inside Syria, most notably an operation in October that freed 70 Iraqi prisoners and an earlier Delta Force raid in May that killed ISIS financier Abu Sayyaf. Operations of that type will likely serve as templates for future actions.

There is, of course, a question of whether the new deployment will involve anything beyond collecting battlefield intelligence, but the clear implication of the Carter comments is that the JSOC soldiers, who are trained in recruiting, training and running spies, will be doing just that in an effort to locate and engage ISIS cadres. Jeff Stein, a well-informed former military intelligence officer writing for Newsweek, believes that “American spies are going to be back in action in a big way against the Islamic State…”

Human agent spying, the second oldest profession if not the first, has oddly been eschewed by many in the federal intelligence community’s war against terrorist groups because of its alleged expense. In reality, the costs of HUMINT are far lower than technical collection, which requires a large initial outlay for development and construction of equipment combined with an expensive infrastructure to operate. Indeed, the cutback in the spy culture at CIA came about because running drones and surveillance satellites was taking so much out of the budget. It was part of a shift in priorities that also brought a rise in the power of Agency paramilitaries, recently supplanting the senior operations officer managers in the clandestine services division that supervises spies.

Traditional espionage was also looked down upon by elected and appointed government officials who, lacking any appreciation of intelligence sources and methods, demanded instant answers in the pressure cooker world of Washington policymaking. Recruiting a spy to penetrate ISIS or al-Qaeda requires lots of time, patience, and a large measure of genuine understanding of the potential target. It could take months or even years to seed in an agent and develop access to a terrorist group, while a satellite with a camera and microphone could be activated instantaneously.

Lost in the transition was the fact that the spy would collect information that a camera could not while he might well be in place and effective for a long time. Human agents, unlike machines, can also provide information on plans and intentions, actually permitting the frustrating of planned attacks. And they can do so in real time through sophisticated miniaturized electronic devices that link to communications satellites.

Follow the money: Once human spying ceases to be the first priority in the budget it also becomes increasingly ignored as the weapon of choice.

There were also practical reasons to abandon traditional clandestine practices. The terrorist enemy proved adept at using double agents, meaning that CIA case officers began to go to meetings armed, which was rarely the case before 2001. Armed officers gradually evolved into the Agency’s fielding of security protection teams that would guard the meeting, even in some cases picking up the agent, moving him to a debriefing site with a hood over his head, and dropping him off on a street later after a case officer had finished talking to him. It was hardly old fashioned spying and did not follow the cardinal rule for agent management, which was to build rapport so the source would be cooperating willingly or even enthusiastically. The old ways also suffered a major setback when in 2009 a Jordanian double agent blew himself up at Khost Base in Afghanistan, killing seven American employees of CIA.

But as terrorist targets become more savvy about how they are being spied upon by satellite they are able to exploit the vulnerabilities inherent in collecting by microphone and camera. Using phones to plant false leads exhausts resources and confuses those who are doing the targeting and tracking, making the whole process less effective. The consumers of intelligence within the U.S. government have unsurprisingly frequently expressed displeasure with the product resulting from all the tens of billions of dollars of investment in satellites and other technical gear.

So on balance a return to HUMINT is almost certainly a good thing, but it will take considerable time to develop as both the CIA and Pentagon will have to relearn old skills and then apply them to situations on the ground that are volatile to say the least. There will inevitably be a learning curve and the questions will certainly come from Congress and the White House as the process plays out. It is unclear whether government consumers will have the patience to persevere or will instead turn again to the deceptively reliable eye and ear in the sky technology.

Philip Giraldi, a former CIA officer, is executive director of the Council for the National Interest.