Those who believed four years ago that an administration led by Barack Obama would shut down the CIA's controversial fleet of unmanned Predator and Reaper aircraft were clearly not listening closely to what the president actually said during his campaign. Had they read the candidate's public statements, they would have realized that Obama had never actually criticized the use of drones to assassinate terrorist leaders and insurgents.

In fact, his comments presaged his later support of an aggressive campaign targeting Al Qaeda leadership in Pakistan. “It was a terrible mistake to fail to act when we had a chance to take out an Al Qaeda leadership meeting in 2005,” he said during his first campaign. “If we have actionable intelligence about high-value terrorist targets and President Musharraf won't act, we will,” the candidate said.

That's precisely what the administration has done, not just in authorizing the SEAL raid that killed Osama bin Laden in 2011, but also with the use of lethal UAV strikes.

Obama personally approves additions to the so-called “kill list,” a roster of names listing those Al Qaeda-linked operatives who can be targeted for assassination by the CIA's apparently growing covert UAV force, according to a report earlier this year by The New York Times. And that list appears set to grow longer. With signs of base expansion in Africa, the Obama administration is clearly making armed UAVs a central part of U.S. military strategy in the years to come.

Can a secret be secret if it is not secret? It is common knowledge that the CIA operates its own UAVs and that they carry out a significant share of strikes, particularly outside Afghanistan—where there are acknowledged U.S. forces on the ground. However, thin as the CIA fig leaf may be, it provides a layer of cover for actions that are at best questionable under international law.

Although more information has leaked out over the years about how and where the CIA conducts its drone strikes, many details are still obscure. For example, little is known about the number of UAVs the agency operates. As long ago as 2006, the Predator and Reaper production lines included aircraft not allocated to the U.S. Air Force, suggesting that CIA birds may not be included in publicly announced USAF contracts. Yet the number of strikes speaks for itself: The use of lethal drone attacks has increased markedly over the past four years and shows no signs of tapering off. As the Obama administration moves into its second term, it is likely to ramp up its UAV campaign.

The difference between the “shadow wars” of strikes conducted by the CIA and the white world of U.S. military strikes is not always clear-cut. While not talked about publicly, there are indications that the military and intelligence operations are closely integrated. The CIA, for example, does not maintain a separate support structure for its drone operations, often relying on Air Force personnel and bases, and it is possible that the military and CIA exchange targets depending on which one is operating in the area.

Perhaps what is most striking about the secret drone strikes is that they show an unprecedented level of cooperation, and in some cases integration, between U.S. military operations and CIA clandestine activities. Though the CIA's drones are often thought of as distinct, the military and CIA operations are closely linked, using the same infrastructure such as the Combined Air Operations Center to coordinate their strikes. The appointment in 2011 of David Petraeus, the former four-star general in charge of U.S. military operations in Afghanistan, as the head of the CIA, appeared to cement the relationship between the CIA and the military (it remains to be seen what will happen in the wake of Petraeus's recent resignation).

In fact, while press and public attention appears to have focused on strikes in areas that are part of America's “shadow” wars, the real drone war, according to publicly released data, is still in Afghanistan, where the U.S. military had conducted 333 strikes in 2012 as of Oct. 31, according to data released by U.S. Central Command. And the number of drone strikes in Afghanistan has increased progressively each year since 2009, when the number stood at 255.

But the clearest line between CIA and military operations occurs in Pakistan, where it is CIA UAV strikes, rather than military operations on the ground, which lead the hunt for Al Qaeda and insurgent leaders. The U.S.'s expanding drone war in Pakistan has received the bulk of attention not because it is the epicenter of those strikes, but largely because they are conducted in secret by the CIA. Those attacks continue to take place in a bizarre world whereby U.S. officials decline to talk about the strikes, on the grounds that they are secret, yet publicly acknowledge they take place. Pakistan's government, which approves the strikes, publicly criticizes them.

Some of that ambiguity was cleared up earlier this year when Obama publicly acknowledged the strikes for the first time, while answering questions during an online forum. In answer to a question specifically about drones, Obama referred to the strikes in Pakistan's Federally Administered Tribal Areas, known as the FATA. “For the most part, they've been very precise precision strikes against Al Qaeda and their affiliates, and we're very careful in terms of how [they have] been applied,” he said.

Those strikes, he continued, were aimed at “people who are on a list of active terrorists, who are trying to go in and harm Americans, hit American facilities, American bases, and so on.” The drones were to be used against Al Qaeda operatives in the FATA, he said, because it allowed the U.S. to conduct strikes where the U.S. military might not be able to conduct operations.

While Obama's comments did not reveal new information, the fact that the president was willing to finally acknowledge the unacknowledged was itself a significant policy shift. It also follows on what has been a steep rise in drone attacks outside Afghanistan under his administration.

According to the New America Foundation, a Washington-based think tank that has been tracking the strikes in Pakistan based on news reports, drone attacks reached a high-water mark under Obama of 122 in 2010. However, there have been just 43 drone strikes to date in 2012, down from 72 in 2011. Understanding the true reach of those attacks is hampered, however, by the secrecy that covers them. For example, the New America Foundation estimates the number of dead in 2012 between 209 and 328, an understandably wide spread given the lack of independent reporting coming from the regions where the strikes occur.

Nor is it the U.S. alone that is increasing its use of UAV strikes; the U.K. has conducted 248 lethal attacks in Afghanistan, according to a report released in February 2012 by a website called Drone Wars UK, which based its number on U.K. government documents obtained through Freedom of Information requests. The organization said details of only 40% of those strikes have been released.

Outside Afghanistan, Camp Lemonier in Djibouti has become a hub of U.S. Predator/Reaper operations in the Horn of Africa, while also serving as a launchpad for the CIA's strikes in Yemen. Additionally, the U.S. military has reportedly opened up two additional bases to house UAVs: one in Ethiopia and another on the Seychelles islands. The bases are part of an expanding U.S. strategy to target militants in Somalia and elsewhere on the African continent.

Even as U.S. operations expand in Africa, Yemen—home to Al Qaeda in the Arabian Peninsula—remains at the forefront of the U.S. drone wars. There, U.S. strategy has benefited from political leadership that has not only allowed the U.S. military to carry out strikes, but also publicly embraced the strategy.

In a recent trip to the U.S., Yemen's new president, Abd Rabbo Mansur al-Hadi, citing his own air force experience, praised the “high precision” provided by U.S. strikes. “The electronic brain precision is unmatched by the human brain,” al-Hadi told an audience at the Woodrow Wilson International Center for Scholars. Hadi also revealed to journalists during that trip that he personally approves all strikes, which are coordinated with the U.S. through a joint operations center located in Yemen.

Hadi's acknowledgement of the drone attacks also underlies some of the differences between Pakistan and Yemen. The strikes in Yemen have been more limited than in Pakistan, and until recently, have faced fewer allegations of collateral damage and thus less public outrage. More fundamentally, the strikes in Yemen are directed against a group that poses a threat to the central government, and thus gives Hadi more reason to support foreign intervention.

That could be changing, however, particularly in light of a September strike that resulted in more than a dozen civilian casualties, according to local reports. In another controversial operation, a 2011 strike targeting Yemeni cleric Anwar al-Aulawi also killed his American-born 16-year-old son, a U.S. citizen.

While many emphasize the benefits of drones in taking the pilot out of harm's way, the real advantage derived from unmanned vehicles may hinge more on politics than technology: The lack of a pilot in the cockpit allows the U.S. to conduct operations in countries where it would never consider flying armed combat missions. An armed F-16 sent into Pakistan or Yemen to hunt terrorists might be unthinkable for those countries, but an armed drone operated by the CIA is more politically palatable.

Having the CIA run its own drone operations has allowed the U.S. government to conduct operations with relative impunity for more than a decade. While it now acknowledges that such strikes take place, the issue is not debated in open congressional committee hearings (since they fall within the purview of the Capitol Hill intelligence committees) nor discussed publicly in any great detail by administration officials. In essence, the combination of UAVs and CIA cover has allowed the U.S. to extend the battlefield far beyond where the U.S. military is publicly engaged in combat operations, and into countries where the U.S. in years past would have never considered conducting lethal operations.