After years of warning that President Obama's targeted killing program flirted with lawlessness, the United Nations has announced it's investigating the centerpiece of the U.S.'s shadow wars worldwide.

The inquiry will be led by Ben Emmerson, the U.N.'s special rapporteur for human rights and counterterrorism. It'll focus on most of the places that the U.S.'s armed drones and elite special-operations forces operate: Afghanistan, Pakistan, Yemen and Somalia; as well as in the Palestinian territories, indicating that Israel's targeted attacks on Hamas will be a subject as well.

Emmerson's focus will be on an "applicable legal framework" for targeted killing, with a special emphasis on drones – something that the lethal technology employed by the U.S. has outpaced, to the chagrin of many legal experts. Afghanistan is the only declared and internationally recognized conflict zone in which the United States operates, and while the U.S. maintains its strikes outside Afghanistan are legal, that legal premise rests on a 2001 act of Congress that many other nations don't recognize. U.S. strikes have surged in Pakistan so far this year.

What's more, the U.N. promises "a critical examination of the factual evidence concerning civilian casualties." That holds out the chance of creating, for the first time, an internationally established standard for the number of noncombatants who have died in drone strikes and commando raids, the subject of fierce dispute and little official acknowledgement.

Emmerson told a press conference in London that he's going to focus on 25 test cases, seemingly of drone strikes, primarily. (Drone strikes and targeted killings are distinct U.S. efforts – targeted killing often employs drones, but drone efforts go beyond the lethal strikes – that often get conflated.) The Guardian previously reported that Emmerson has expressed concern about so-called "double-tap" strikes, in which U.S. drones attack the debris of earlier strikes when people, including rescue workers, gather to investigate.

Drone critics are cheering the inquiry, which follows years of international-law experts warning the U.S. was dancing on the precipice of lawlessness. "Virtually no other country agrees with the U.S.'s claimed authority to secretly declare people enemies of the state and kill them and civilian bystanders far from any recognized battlefield," said Hina Shamsi of the American Civil Liberties Union. "To date, there has been an abysmal lack of transparency and no accountability for the U.S. government's ever-expanding targeted killing program."

There is so far no indication of the level of cooperation Emmerson will seek from the United States, let alone how much the Obama administration will provide. Emmerson's report is due in the fall.

Typically, inconvenient United Nations pronunciations are ignored inside the U.S. – when they're not insulted outright by a U.N.-wary political class. Yet dozens of nations are experimenting with drone technology, including U.S. adversaries like Iran, prompting fears of an unmanned, robotic arms race. That's probably not the biggest U.S. concern, given the overwhelming U.S. robotic advantage, especially in on-deck drone tech like the Navy's forthcoming carrier-based armed drone. But even if the U.S. doesn't like his work, Emmerson might represent the first wave of an international legal framework governing a technology that doesn't right now clearly follow one – which might also give legitimacy to at least some robotic or targeted killing efforts.