WHEN THE Senate Select Committee on Intelligence released its “torture report” in December 2014, it reignited the battle over the George W. Bush administration’s conduct of the “war on terror.” Unfortunately, the interrogation program was not an anomaly in its lack of transparency. A similar problem exists with the U.S. drone program—which, after more than ten years of use and nearly two years after President Barack Obama’s speech promising greater transparency and accountability, remains shrouded in secrecy and uncertainty.

If an internal critique of the U.S. drone program exists, it has been kept from open discussion and debate. Yet the most basic questions about the program have not been answered: What are the goals of the program? Are drones effective in accomplishing those goals? What metric is used to evaluate their effectiveness? Such queries arise at an important moment in American history. The Obama administration is faced with defining its legacy. The administration, which inherited two wars, has struggled with the dilemma of winding down military actions in Iraq and Afghanistan at the same time that threats from new adversaries have created new challenges for U.S. and international security. In response, the administration has relied heavily on the use of drones, which has allowed them to avoid further on-the-ground engagement, but has raised many legal, ethical and strategic questions in the United States and around the world.

Those critical of the U.S. drone program are quite reasonably asking whether strikes—particularly in Afghanistan, Pakistan and Yemen—are achieving measurable gains beyond an estimated four thousand deaths of largely unidentified males. Instead, they argue that continued (and unaccountable) drone attacks are actually alienating foreign populations and governments. Without a reasonable and clear metric, it is impossible to determine whether strikes should be continued, whether the program should be scaled back or even whether it should be halted altogether.

Without a clear enunciation of U.S. drone policy, oversight is inhibited. The result is greater ambiguity. This cycle of uncertainty compromises the ability to determine whether current drone use is effective in accomplishing national-security objectives. As America continues to rely upon air strikes as a central pillar of its counterterrorism strategy—more recently exemplified by its air campaign against the Islamic State—and expands operationalization of drones, it must emphasize developing and releasing clear policy goals that are consistent with U.S. national-security objectives and foreign-policy ideals. Only then can policy makers determine whether current strategy is effective and is achieving long-term goals.

DRONES AND their use by the United States are largely shrouded in mystery. Some see them as an essential counterterrorism tool; others see them as foreshadowing a future out of The Terminator in which drones and autonomous weapons target and fire at will. The White House’s secrecy regarding its drone policy has not done it any favors, and has allowed misconceptions of the program and of drone technology in general to flourish. A prominent example was Senator Rand Paul’s 2013 filibuster of John Brennan’s nomination to head the CIA, in which the senator conjured up a scenario where Americans sitting in cafés might find themselves unexpectedly targeted by Hellfire missiles.

The Obama administration has put forward a wealth of rhetoric supporting the idea of transparency. In his 2013 speech at the National Defense University (NDU), Obama underscored the importance of transparency and accountability for the U.S. drone program. The president pledged to “review proposals to extend oversight of lethal actions outside of war zones that go beyond our reporting to Congress.” He also noted that “the use of force must be seen as part of a larger discussion we need to have about a comprehensive counterterrorism strategy.”

The president raised the issue of effectiveness in his NDU speech, saying that effectiveness should not be confused with good policy or moral decision making. In his words:

As our fight enters a new phase, America’s legitimate claim of self-defense cannot be the end of the discussion. To say a military tactic is legal, or even effective, is not to say it is wise or moral in every instance. For the same human progress that gives us the technology to strike half a world away also demands the discipline to constrain that power—or risk abusing it.

While Obama’s remarks were welcomed at the time, the impact of his words was limited. A year later, when the president delivered a speech at West Point, little outward progress had been made in clarifying U.S. policy. The president echoed his NDU talking points and again highlighted the risks involved in not being clear and transparent about U.S. counterterrorism policy:

But as I said last year, in taking direct action we must uphold standards that reflect our values. That means taking strikes only when we face a continuing, imminent threat, and only where there is . . . near certainty of no civilian casualties. For our actions should meet a simple test: We must not create more enemies than we take off the battlefield.

In short, the president recognized that not being transparent and accountable could come at a cost and create long-term risks, saying that when the United States “cannot explain our efforts clearly and publicly, we face terrorist propaganda and international suspicion, we erode legitimacy with our partners and our people, and we reduce accountability in our own government.”

But while Obama has paid significant lip service to transparency, his administration’s actions have fallen short of this promise. Under pressure and court order, the administration did release two memos detailing the legal rationale behind targeting U.S. citizens with drone strikes, but the administration has not been forthcoming with the release of documents that outline the United States’ overarching strategy, concrete objectives or end goals. In fact, nearly two years after the president’s NDU speech, the only new policy of note came with the release of export guidelines for drones in February 2015.

ONE MEASURE of drone efficacy is analysis of the known U.S. drone strikes. Since 2004, the United States has conducted about five hundred drone strikes in Pakistan, Yemen and Somalia, based on research provided by the New America Foundation, the Long War Journal and the Bureau of Investigative Journalism. Micah Zenko has reported that fifty of those strikes were conducted under Bush, while four hundred and fifty were under Obama. The United States is now believed to have used drone bases in at least twelve countries: Afghanistan, Djibouti, Ethiopia, Kuwait, Niger, the Philippines, Qatar, Saudi Arabia, Seychelles, Turkey, the United Arab Emirates and Yemen.

The use of drones is an integral part of the strategy against the Islamic State, and the United States is known to be carrying out air strikes in Syria and Iraq using both manned and unmanned systems. But beyond measuring casualties and identifying high-level targets that have been killed, the metric for gauging effectiveness is unclear. And, as Obama himself noted, the deaths of innocent civilians among the “legitimate” targets can turn populations against the United States and undermine its counterterrorism efforts.

Still, Washington remains committed to targeting high-level Al Qaeda, Al Qaeda-affiliated and Taliban leaders, particularly in Pakistan. The New America Foundation and the Long War Journal have produced lists containing details on sixty-four high-level leaders reportedly killed by the U.S. drone program in Pakistan, including targets identified as weapons and explosive experts, commanders and planners, and other senior leaders. They include Osama al-Kini, Al Qaeda’s then chief of operations in Pakistan; Badar Mansoor, thought to be Al Qaeda’s most senior leader in Pakistan; and Hakimullah Mehsud, commander of the Pakistani Taliban. These targets are perhaps much less well known than the American citizen Anwar al-Awlaki, who was targeted in Yemen for his role as an “operational terrorist leader” and his participation in planning attacks on Americans.

The targeted-killing program has been ongoing for more than a decade. But there remains troubling uncertainty regarding the legal basis for the program under both domestic and international law. Under U.S. law, the 2001 Authorization for Use of Military Force authorizes lethal force against “those nations, organizations, or persons [the president] determines planned, authorized, committed, or aided the terrorist attacks that occurred on September 11, 2001.” To date, the administration has interpreted this legislation broadly, saying that it covers the Taliban, Al Qaeda and their “associated forces.” However, it remains unclear who the U.S. government identifies as “associated forces,” or how combatant status is determined, or how “participation in hostilities” is defined.

The law of armed conflict has provided the international legal basis for U.S. action against Al Qaeda and the Taliban. However, as U.S. involvement in emerging and ongoing conflicts evolves, and the threat of nonstate actors increases, uncertainty about whether U.S. drone use is consistent with rule-of-law standards is growing. This absence of clarity arises from the lack of a designated “battlefield,” along with confusion about what counts as “hostilities” and who should be considered “combatants.” Moreover, questions regarding the U.S. definition of an “imminent threat” risk undermining U.S. action.

The secrecy surrounding the drone program, particularly the aspects under CIA control, makes oversight and proper accountability difficult, as it is unclear who is involved in the process, how the chain of command works and who is ultimately responsible for strikes. Washington will need to focus on creating clear rules, even for the covert aspects of its drone program, that contain strong accountability measures and a precise determination of the state and nature of the conflict.

ALTHOUGH THE U.S. drone budget had been shrinking, current campaigns in Iraq and Syria and potential new uses elsewhere are likely to breathe new life into the drone program. The technology is already a key component of the United States’ defense and national-security strategy. The Pentagon’s fiscal year 2016 budget requested $2.9 billion for drones, of which nearly $1.2 billion was for research, development, testing and evaluation.

In a speech at the Reagan National Defense Forum in November 2014, Secretary of Defense Chuck Hagel introduced a new “Long-Range Research and Development Planning Program” that will emphasize research and development in the fields of robotics and autonomous systems, among others, which indicates an extended and potentially sustainable emphasis on the development of drone technology—a big boon to U.S. drone producers who had long complained that overly restrictive regulations were stifling U.S. competitiveness and innovation. The United States has begun to step up its investment in drone technology. At the same time, twenty-three countries have developed or are developing armed drones, according to a 2014 RAND Corporation report, and more than seventy countries have acquired drones of different classes and for different purposes.

The United Kingdom and Israel are the only countries besides the United States to have employed armed drones, but a number of European nations are seeking to develop such technology in order to better compete in the growing drone market. In 2013, seven European countries formed a “drone club” with the goal of developing a “European generation” of drones over the next ten years. And, according to a June 2014 Council on Foreign Relations report, advancements in technology will only make drones more readily accessible to governments and nonstate groups around the world.

The Teal Group Corporation estimates that the drone market will nearly double over the next ten years, increasing from the current $6.4 billion to $11.5 billion. Although the current market is made up of 89 percent military technology and 11 percent civil technology, it is estimated that these percentages will shift to 86 percent military and 14 percent commercial by 2024. Meanwhile, the lines between what is military and what is civilian will continue to blur.

With drone technology expected to proliferate widely in the next decade, it is increasingly important for the United States to establish a clear policy and responsible standards for use. The lack of clarity risks creating a precedent for use mired in secrecy and ambiguity that other countries will follow. As more countries develop and acquire drone technology, and as the technology continues to evolve, it is critical that the United States ensure that drones are used in ways that support, rather than undermine, U.S. interests.

THE DISCOURSE on drones is changing, at home and abroad. The technology itself is evolving in size, shape and form. The definition of the human role in deploying drones is also shifting as technological advances in automation and autonomy take place. And, in even more practical terms, the numbers of uses and users, both commercially and militarily, are increasing at a rapid pace. These changes are influencing discussions on policy and on the conduct of war more broadly. While it is important to make the distinction between the instrument and the nature of war itself, it sometimes appears as though the Obama administration and military officials see drone technology as a panacea for fighting modern wars.

The U.S. government sometimes seems conflicted about the efficacy of drones and targeted killings. A secret CIA report released by WikiLeaks in December 2014 highlights the tensions surrounding the U.S. drone program. The report says that targeted killings can “strengthen extremist groups and be counterproductive.” Although the targeting of high-value leaders can be effective in undermining organizational structures, it can also be responsible for “increasing violence and greater popular support for extremist groups.” The report, which was conducted by the CIA in 2009, highlights the fact that drone strikes “may increase support for the insurgents, particularly if these strikes enhance insurgent leaders’ lore, if noncombatants are killed in the attacks, if legitimate or semilegitimate politicians aligned with the insurgents are targeted, or if the government is already seen as overly repressive or violent.” However, the CIA study also says that drone strikes and targeted killings could be beneficial if they are “part of a broader counterinsurgency strategy that employs other military and nonmilitary counterinsurgency instruments.”

More rigorous study of the costs and benefits of U.S. drone use and the targeted-killing program in general is imperative. In June 2014, the Stimson Task Force on U.S. Drone Policy (for which I served as project director) released a report challenging the Obama administration to develop a comprehensive drone policy. It called on the administration to take short- and long-term steps that would provide clarity for the U.S. drone program. Although some of the recommendations require congressional action and further bureaucratic changes, there were several recommendations that can be addressed through executive order, which would allow the Obama drone legacy to be more than just a record number of strikes.

In the short term, the Obama administration should conduct a rigorous strategic review and cost-benefit analysis of lethal drone strikes, particularly in counterterrorism operations. No congressional approval for such a study would be necessary, and the results could help solidify a clear course for U.S. action. The U.S. government must also make tangible improvements to transparency efforts. Greater transparency has a twofold impact: it engenders public confidence domestically and can serve as a global confidence-building measure, and it improves oversight and accountability.

What would increased transparency look like in practice? First, the administration must provide a report that contains the domestic and international legal bases for the U.S. drone program. The administration’s public statements have not been sufficient in explaining the legal rationales. Transparency should also include the provision of historical data on U.S. strikes to allow for better understanding of how the drone program has been used. It could entail identifying the number of strikes in a given location, the number of casualties, the organizational affiliations of those killed, the identities and numbers of civilian casualties, and who conducted the strikes—all of which can be provided after the strikes have occurred, perhaps with a short delay for security reasons. Aggregate data, without specific details, could be provided as an interim measure.

Greater oversight and accountability can ensure that the U.S. drone program is conducted in compliance with U.S. and international law and also that it is indeed an effective tool in the conduct of U.S. military operations. It will be crucial to identify and implement a mechanism that can review strikes in real time and determine whether there have been errors or successes, and whether the strikes are achieving strategic goals. Transferring the responsibility for strikes from the CIA to the military will make oversight easier, but even for operations that must remain covert, a clear process must be incorporated to encourage evaluation of the drone program. Without oversight and accountability, the program cannot be systematically evaluated and adjusted. Moreover, greater clarity will help develop an effective and useful international precedent and foster the development of appropriate norms for drone use, particularly in settings outside of traditional battlefields.

THE OBAMA administration has less than two years to cement its legacy. It’s time to develop a long-term drone strategy that boosts understanding of and confidence in U.S. decision making and sets an example for other countries for their own drone programs. The United States must find a way to balance legal and ethical frameworks with national-security concerns and commercial innovation. Only a comprehensive U.S. policy that takes security, foreign-policy and commercial interests into account can turn around the negative international view of the technology and U.S. authority on the issue.

The Obama administration must be clear that drones are not a strategy in and of themselves, but rather a tactic in the service of what should be a larger, more clearly articulated strategy—whether for counterterrorism or for other military aims. A clear and convincing articulation of that strategy would illustrate the ways in which drones could be used to support America’s foreign-policy objectives. Anything short of that could jeopardize the very aims that the drone program seeks to further.

Rachel Stohl is a senior associate with the Managing Across Boundaries Initiative at the Stimson Center and was project director of Stimson’s Task Force on U.S. Drone Policy.