When a US drone attack killed members of a wedding party outside the city of Rad'a, Yemen, in December, it appeared to directly contradict US President Barack Obama's earlier promise that such attacks would only be undertaken when a "near-certainty" could be reached that no civilians would be killed.
That strike, which killed 12 and wounded 15, including the bride, may have killed members of al-Qaeda in the Arabian Peninsula, although neither the US nor Yemeni governments have provided information about the intended targets, or the alleged terrorist activities of those involved in the party. But a report released last month by Human Rights Watch claims those killed were civilians, and calls into question the legality of the attack.
Letta Tayler, a senior researcher specialising in terrorism and counterterrorism, authored the report "A Wedding That Became a Funeral". "We at Human Rights Watch question the global war theory that President Obama uses to justify targeted killings of terrorism suspects," she told Al Jazeera. "We recognise that terrorist groups are a serious threat to the US. We recognise that al-Qaeda in the Arabian Peninsula is one of these groups. But we are not convinced, based on the information we've seen, that the level of hostility with these groups rises to the level of an armed conflict. And if it does not, then the laws of war do not apply."
|People & Power - Attack of the drones
These laws of war are at the heart of the controversy over drone missile strikes, or targeted killings. Article 51 of the Geneva Convention states, "The civilian population and individual civilians shall enjoy general protection against dangers arising from military operations," with the caveat: "unless and for such time as they take a direct part in hostilities".
Dr Mary Ellen O'Connell, professor of international dispute resolution at Notre Dame University, who wrote numerous books on international law, and an outspoken critic of the US' targeted killings calls the label "civilian" a misnomer.
"Distinguishing some casualties as 'civilian' is a trap set by the administration to get us to think that what they're doing is somehow lawful because there are these people who are quasi-combatants and therefore, we have the right to kill them," O'Connell told Al Jazeera.
"We are killing people with drones and other means outside our conflict zones, in Yemen, in Pakistan and in Somalia," she said. "In these three countries, everyone we kill is a civilian and the only number that matters is total numbers."
"Nobody in that (wedding) convoy was a lawful target because the United States is not at war with Yemen," she said. "We need to stop entering into the world of false mirrors that the administration has been setting up and diverting us from questioning the policy."
In an interview with Al Jazeera, a former US senior intelligence officer pointed to the ability of drones to locate and track alleged terrorists in remote, ungoverned and inaccessible areas. "We conduct targeted killings outside of internationally recognised zones of conflict, or internationally-agreed theatres of conflict," the former official said. "And that makes us unique. None of our Western allies think that is an appropriate policy."
"We have a view of this conflict that is different than our allies. And what's most incredible is that two incredibly different presidents have the same view. It's a global war. We think the battlefield is global, and are entitled to use targeted killings in circumstances where there is great danger to us and the sovereign in that territory is either unwilling or unable to take action."
The US targeted killing policy has never been made public. Obama's speech in May 2013 is the closest the administration has come in outlining guiding principles for the programme that began in 2002, under then-President George W Bush. In that address, Obama defended the programme, stating, "This is a just war, a war waged proportionally, in last resort and in self-defence."
Obama then used a phrase that remains a sticking point for both advocates and opponents of the targeted killing programme: "Before any strike is taken, there must be near-certainty that no civilians will be killed or injured."
Drones allow a level of precision and patience that is greater than anything we've seen before.
Republican Congressman Buck McKeon from California, Chair of the House Armed Services Committee, has been a staunch advocate of the expansion of the drone industry for not only targeted killings, but surveillance, and other non-lethal tasks. Speaking at the National Press Club in Washington, DC, McKeon said, "There's no question there have been civilians killed, and that there have been civilians killed in every war that has ever been fought on this planet. I would say probably fewer in this war [as a result of drone technology.] We'd rather have our enemies die than our troops, and anything that carries out that mission is something we should be happy that we have. I never want to send our troops into a fair fight. That doesn't make sense."
Defenders recognise that while not an exact science - drones remain an effective and useful way to strike suspected enemy targets.
"Drones allow a level of precision and patience that is greater than anything we've seen before," said the former senior intelligence officer. "With all that said, do we make mistakes? Yes. With all that said, are there times when you know there may be civilian casualties, but the significance of the target means you go ahead and do it anyway? Yes."
In his speech in May, Obama said, "To say a military tactic is legal or even effective is not to say it is wise or moral in every instance. The same progress that gives us the technology to strike half a world away also demands the discipline to constrain that power or risk abusing it."
Whether the targeted killing programme is ruled more by restraint or abuse may never be known publicly. "There are aspects of the target[ed] killing programme that remain classified, despite everyone seeming to know about it, and it being discussed pretty freely," said the former senior intelligence official. "It's not as easy for the government to put out a full-sum document."
And as for the attack on the wedding party in Yemen in December? The former official said, "The US government is sticking to its story: They hit what they wanted to hit and they remain convinced that only bad people died."