That was a central question Wednesday as the program came under fire from several legal scholars who called for greater oversight by Congress, arguing the attacks may violate international law and put intelligence officers at risk of prosecution for murder in foreign countries.
Four law professors offered conflicting views, underscoring the murky legal nature of America's nine-year-old war against extremists. The conflict has spread from wars in Iraq and Afghanistan to a complex campaign against al-Qaida, the Taliban and other insurgents worldwide.
Both the Bush and Obama administrations have defended the use of attacks from unmanned aircraft. But they have also tiptoed around the issue because the CIA program — which has escalated in Pakistan over the past year — is classified and has not yet been acknowledged publicly by the government.
The CIA strikes are "a clear violation of international law," said Mary Ellen O'Connell, law professor at the University of Notre Dame Law School, who added that going after terrorists should be a law enforcement activity.
She said the rest of the world does not recognize American authority to carry out attacks in Yemen and Pakistan, countries where the U.S. is not involved in direct armed conflict.
CIA officers who operate the drones could be arrested and charged with murder in other countries, O'Connell warned, likening it to having the Mexican police or military bomb hotels in Arizona in order to target drug lords who may be hiding there.
Others on the panel disagreed, saying enemy forces are legitimate targets, particularly when they operate out of countries that won't take action themselves.
The U.S. has long declared the legal view that as important as sovereignty is, "it is lawful to go and strike a person where a country is unable or unwilling" to control its own territory, said Kenneth Anderson, a professor at American University's Washington College of Law.
CIA spokesman George Little would only say Wednesday that the CIA's counterterrorism operations are conducted in strict accord with the law.
Anderson's comments echoed remarks last month by State Department legal adviser Harold Koh. In a carefully worded speech, Koh said the Obama administration is committed to following the law in its operations against terrorists.
And, while noting that there were limits to what he could say on the matter, Koh added that "U.S. targeting practices, including lethal operations conducted with the use of unmanned aerial vehicles, comply with all applicable law, including the laws of war."
Anderson said the secrecy around the program — which is written about extensively in the media — has become counterproductive for the CIA. He said it's difficult for the administration to give a legal blessing to something the agency doesn't admit takes place.
An open discussion about the legal and policy issues would be more helpful, he said, and also would provide better legal protection for the CIA and the employees involved in the strikes.
Lawmakers and the professors were also divided on the administration's move to put Anwar al-Awlaki, a U.S. born Muslim cleric who has been linked to the recent attacks against America, on the CIA's list of terrorists to be killed or captured.
O'Connell said the idea that the U.S. can go after anyone it wants is "a fiction created by lawyers."
The U.S. she said, should be working with countries like Pakistan and Yemen, and not treat them like combat zones or dismiss them as unwilling or unable.
David Glazier, professor at the Loyola Law School in Los Angeles, argued that enemy forces are legitimate targets anywhere. He said if a neutral country gives its consent or is not being helpful, it has historically been considered lawful to do limited operations in countries not directly involved in a conflict.
The U.S. has worked with the militaries in both Pakistan and Yemen, providing training and equipment as well as intelligence and surveillance assistance. And, according to officials, the U.S. has participated in strikes either at the request of the host country or with its implicit approval.
Rep. John Tierney, chairman of the House Oversight subcommittee that held the hearing, acknowledged that he did not expect quick answers to all the legal questions. But the Massachusetts Democrat said Congress and the administration must begin to talk about the issue more openly.