Leading article: Drone attacks must not be hidden from the law

President Obama has presided over a tenfold increase in attacks in Pakistan

Of the long list of controversial military developments, the rise of the unmanned aerial vehicle – the "drone" – is one of the most contentious yet. All the more reason, then, for the US, as the technology's main proponent, to take all possible measures to ensure that the use of drones is within international laws of combat. If only.

The row about drones is not going to go away. The US may lead the field, with more hours now flown by unmanned than by manned fighters and UAVs used against targets from Afghanistan to Yemen. But it is far from alone in its appetite for remote warfare. More than 50 countries have the use of drones of some kind – they played a key role in Nato's support of the Libyan revolution last year, for example – and British Reapers have carried out as many as 200 strikes in Afghanistan alone.

It is easy to see why UAVs are proving so popular. Considered in purely military terms, there is much to recommend them. They are cheaper and more discrete than traditional fighter jets and are not limited by issues of fatigue, boredom, or manoeuvrability entailed by having a human pilot on board. They are also hugely versatile, bristling with sophisticated technology that can be deployed for reconnaissance, surveillance and highly targeted missile strikes. Most appealing of all, they can be controlled from anything up to 7,500 miles away, keeping troops well out of harm's way.

All of which, supporters say, make drones the perfect modern weapon, ideally suited to taking on stateless terrorist groups such as al-Qa'ida, whose members may be spread throughout any number of countries, making it neither practically possible nor politically expedient to put boots on the ground.

Compelling though such arguments may be, they gloss over any number of questions, both moral and legal. While few would advocate that their country's military personnel be exposed to unnecessary danger, the stark inequality of risk in a drone attack nonetheless raises ethical qualms. That a controller might dispatch any number of people – terrorists or not – from the safety of thousands of miles away, and then go home in the evening like any other office worker, elicits similar concerns.

Meanwhile, there is the real danger that, by removing the risk of physical harm, drones remove some restraint on action, increasing the likelihood of violence. Highly conflicting reports of the number of civilians killed in such attacks only muddy the waters further.

While there are no easy answers as regards the ethics of drones, the legal issues are rather easier to quantify – or they would be, if the US were to co-operate. The issue is not so much the Geneva Convention; rules governing the use of weapons systems are as applicable remotely as on the ground. But while the use of drones in a conflict zone such as Afghanistan is one thing, their deployment in the tribal areas of Pakistan, say, is another matter entirely.

In an interview in this newspaper tomorrow, Ben Emmerson, the United Nations' special rapporteur on human rights and counter terrorism, stresses that the issue will "remain at the top of the UN political agenda until some consensus and transparency has been achieved". Quite right. Yet the Obama administration –which has presided over a tenfold increase in drone attacks in Pakistan – refuses even to confirm or deny the existence of the programme, let alone to release the visual recordings of strikes to allow independent assessors to establish the legality of their actions.

Drones are profoundly changing the terms of combat, and will continue to do so. If the ethical issues cannot be easily resolved, it is in the interests of all, including the US, to ensure their deployment is at least legal. And that means a reasonable transparency about their use.