Questions have arisen about the legality of the Obama administration’s use of unmanned aerial drones as part of U.S. counterterrorism efforts in Afghanistan, Pakistan’s Afghan-border region and Iraq.

Proponents of remotely targeting the enemy off the battlefield and delivering weapons from drones say it is legitimate and it saves the lives of innocent civilians and American soldiers without putting pilots in harm’s way. Some legal scholars and critics have said that it violates the rules of war and international law and has caused collateral civilian deaths. The use of drones for targeted strikes against al-Qaeda and the Taliban, while presenting some unresolved issues, is a lawful and appropriate utilization of modern weaponry in a time of war.

There is something troubling when acts of violence – such as firing a missile with a massive payload delivered by a plane flown remotely via a video uplink to a satellite – become so impersonal and detached. Capable of killing dozens of people with a single press of a button, the pilot of a drone doesn’t hear screams or see blood-he just watches as a cloud of gray dust fills his computer screen. It has an almost antiseptic quality to it. Certainly it is easier to take risks with unmanned planes operated from a trailer in Nevada rather than while stationed in Afghanistan. Further so with planes operated by joystick that cost less than $5 million apiece compared to complex, difficult-to-fly fighter jets that cost as much as $150 million.

The United Nations Special Rapporteur for Extrajudicial Executions has questioned whether it is lawful for the U.S. to target and execute individuals off the battlefield. Professor Mary Ellen O’Connell of Notre Dame Law School has called the use of drones “unlawful killing,” and says it violates international law. The American Civil Liberties Union has filed a Freedom of Information suit in a bid to require the federal government to divulge details about the classified program, such as who authorizes strikes and the damage they cause.

Since 2001, when the drone program began, the U.S. has been at war with al-Qaeda and the Taliban. As its main authority to track and kill suspected al-Qaeda members, the Obama administration has relied on a congressional resolution that authorized President George W. Bush to “use all necessary and appropriate force against those nations, organizations, or persons” deemed linked to the Sept. 11, 2001 terrorist attacks. Intelligence officials estimate approximately 500 suspected al-Qaeda militants and terrorist leaders have been killed by drones. The Air Force conducts drone missions in Iraq and Afghanistan. The Central Intelligence Agency oversees drone flights in Pakistan.

In a speech this spring to the American Society of International Law, State Department Legal Advisor Harold Hongju Koh countered those critics with a compelling legal argument justifying the use of drones for targeted strikes to kill terrorists overseas, on or off the battlefield. The U.S. has the right to exercise its “inherent right of self defense,” including strikes against terrorist leaders, argued Mr. Koh, the former Dean of Yale Law School and the 2009 recipient of the Law Tribune’s Service to the Profession Award.

“In this ongoing armed conflict,” Mr. Koh said, “the United States has the authority under international law, and the responsibility to its citizens, to use force, including lethal force, to defend itself, including by targeting persons such as high-level al-Qaeda leaders who are planning attacks.” Targeting a particular person is not unlawful killing and does not violate the rules of war, he said, because “individuals who are part of such an armed group are belligerents and, therefore, lawful targets under international law.”

Ironically, Mr. Koh, an outspoken critic of most of the Bush administration’s policies regarding the war on terrorism, articulated a strong defense of the prosecution of the war itself: “This is a conflict with an organized terrorist enemy that does not have conventional forces, but that plans and executes its attacks against us and our allies while hiding among civilian populations.”

While the drone campaign may be lawful and effective, as evidenced by the killing of al- Qaeda’s operations chief in late May, the CIA is a civilian agency and noncombatant under International Humanitarian Law that is not governed by the same laws of war that cover U.S. military personnel. Its role should be clarified.

Meanwhile, because its benefits clearly outweigh the costs and risks, and there is a strong legal rationale for it, the drone program should continue.