Every weapons system, from the bow and arrow to the intercontinental ballistic missile, sometimes kills the wrong people. So why has the revelation that a US drone strike accidentally killed two Al Qaida hostages — a US citizen and an Italian aid worker — created such a storm of drone “rethinking”?

Part of the answer is that liberal critics of drone strikes, who’ve questioned their legality, are using the opportunity to repeat and reframe their criticisms. I’ve joined in some of that criticism in the past and stand by it.

But the deeper reason for the renewed discussion is a pernicious myth: the fantasy that drones are uniquely precise. From the start, this fantasy of precision has been at the heart of the political and tactical appeal for President Barack Obama. The same myth has also been central to legal criticisms of the strikes, from the standpoints of US constitutional law and of international law.

Start with the appeal of drones. The intelligence community was the first to be smitten, not for drones’ capacity to strike but for their ability to circle repeatedly and gather detailed information without creating risk to US pilots. As an intelligence-gathering tool, unarmed drones are in fact highly distinctive. Satellites can take increasingly precise photographs without being noticed, but most can’t point their cameras at one place for very long. Of course, if a satellite is on a geosynchronous orbit, it can aim at a specific target indefinitely — but then it can’t look anywhere else unless you move it, which requires substantial effort. Drones are much more nimble.

This information-gathering advantage sparked, I think, the fantasy of drone precision in air strikes. It’s true that the operator of an armed drone can deliver a missile to a site that’s been carefully scooped out by other drones. But conventional aircraft could use that same intelligence to deliver missiles with similar precision (and a similar margin for error).

The real military advantage of the armed-drone strike over a conventional air strike, then, isn’t the precision of the hit. It’s the fact that a pilot isn’t being put in jeopardy. Yet somehow the idea that drone strikes are more precisely targeted has lingered, giving the technique greater public appeal.

There can be little doubt that the Obama administration benefited politically from this aura of precision. If the characteristic George W. Bush bombing tactic was “shock and awe”, the technologically sophisticated Obama’s signature became targeted drone strikes. It’s an easy sell: the use of smart power to kill only the bad guys.

At the same time, the fantasy of precision had a substantial legal downside. No one believes that an American army fighting in the battlefield against an enemy that includes a handful of US citizens would owe any special legal duty to the Americans fighting for the enemy. Yet a memorandum written by the White House’s Office of Legal Counsel argued that Americans who would be targeted in drone strikes apparently deserved constitutional protection under the due process clause.

Astonishingly, this crucial memo has still not been released in full, despite repeated promises by the administration to release it — and despite the fact that its author is now a federal appellate judge. Parts of the memo argued that due process was satisfied by an internal White House review process, one that didn’t include the opportunity for arguments before a neutral decision maker, traditionally the core of due process.

But due process is what an individual gets if put on trial — emphasis on “individual”. That standard could apply to drone strikes only if you imagined drones as highly targeted weapons rather than generalised bomb strikes.

The fantasy of precision was also at the core of international legal criticism. Critics like a special rapporteur appointed by the UN, Philip Alston, focused on international legal prohibitions on targeted, extra-judicial killings. No one applies such terms to ordinary warfare — even though ordinary bombs kill people without due process.

To be sure, these criticisms had and have legal bite. There is something different about a military attack that aims to kill particular individuals. But legally speaking, the criticisms should apply with equal force to a conventional air strike that uses the same targeting criteria.

When it comes to drones, the fantasy of precision is just that, a fantasy. Killing innocent civilians, whether they’re Americans or Pakistanis or Yemenis, is an inevitable reality of war. The right criteria to analyse attacks are the familiar ones of policy and law: Is the strike justified? Is it aimed at a military target? Is it proportional?

To answer those crucial questions, we need to start from facts, not fantasy.

— Washington Post

Noah Feldman is an American author and professor of law at Harvard Law School