Drone pilots could be given medals for killing Isis fighters while operating in bases thousands of miles from the combat zone, Defence Secretary Sir Michael Fallon has announced.

On a visit to British troops in Iraq, Sir Michael signalled a possible shift towards awarding medals to those facing mental strain, and not just to combatants who have been physically exposed to danger.

He said the increasing use of “cutting-edge equipment” meant it might be time to pin medals on drone pilots conducting remote-controlled airstrikes from bases in Lincolnshire and Nevada as part of Operation Shader against Isis in Iraq and Syria.

He said: “The changing character of warfare provides new challenges - not just about how we fight but also how we recognise and support those who serve.

"As fighting has evolved we have adapted, ensuring our troops have cutting-edge equipment including unmanned systems operated from outside the battle space. Our recognition of service, the risks taken, and the long-term effects must therefore adapt too.

"That is why we need to examine how to provide medallic recognition for those making a vital contribution to Op Shader outside the battlespace, from Reaper pilots taking life-and-death decisions to those who ensure our planes can strike Daesh [Isis] targets."

His announcement coincided with journalists being shown footage of an RAF drone strike that stopped an Isis execution, and being told by the Air Commodore in charge of Operation Shader that drone strikes in Iraq and Syria had helped prevent potential terror attacks in the UK.

That, though, is unlikely to dampen the controversy around giving medals to drone pilots.

Critics of drones have repeatedly argued that they introduce a ‘Play Station mentality’ into real-life killing, and tempt rich nations to carry ever more “extrajudicial killings” of terrorist suspects in developing countries.

In 2013, while still a backbencher, Jeremy Corbyn called the use of drones an “obscenity”.

In remarks later seized upon by Tory critics during this year’s General Election, Mr Corbyn told protesters outside RAF Waddington in Lincolnshire, from where drone missions are controlled: “Just as much as we want to get rid of landmines, small arms, nuclear weapons, we want to get rid of drones as well.

“They are the ultimate in sanitised warfare, where you immunise yourself against the reality of it, knowing full well that a family with barely enough to eat are going to be killed by a multi-million pound weapon at the press of a button by someone in an air-conditioned office in the mid-west of the USA or Lincolnshire."

In June this year, however, Dr Peter Lee, a Portsmouth University academic who had conducted “field research” among RAF Waddington Reaper drone crews, told MPs on the All Party Parliamentary Group on Drones that the operators deserved medals.

In pictures: Isis' weapons factories Show all 11 1 /11 In pictures: Isis' weapons factories In pictures: Isis' weapons factories A mortar round fin manufactured by Isis in Gogjali, Mosul, November 2016 Conflict Armament Research In pictures: Isis' weapons factories Isis rocket components discovered in Gogjali, Mosul, Iraq in November 2016 Conflict Armament Research In pictures: Isis' weapons factories Isis mortars discovered near Karamlais, Iraq, in November 2016 CAR In pictures: Isis' weapons factories An Isis rocket launch frame in Qaraqosh, November 2016 Conflict Armament Research In pictures: Isis' weapons factories A memo from Isis' COSQC on quality control at a manufacturing facility in Gogjali, Mosul, November 2016 Conflict Armament Research In pictures: Isis' weapons factories Electrically-operated initiators manufactured by Isis in forces Gogjali, Mosul, November 2016 Conflict Armament Research In pictures: Isis' weapons factories Isis mortar tubes at a manufacturing facility in Karamlais, November 2016 Conflict Armament Research In pictures: Isis' weapons factories An Isis mortar production facility discovered in Gogjali, Mosul, in November 2016 Conflict Armament Research In pictures: Isis' weapons factories An Isis weapons manufacturing facilities near Mosul in November 2016 Conflict Armament Research In pictures: Isis' weapons factories Stocks of French-manufactured Sorbitol, Latvian potassium nitrate and Lebanese sugar at an Isis weapons factory in Iraq Conflict Armament Research In pictures: Isis' weapons factories A destroyed Isis weapons facility in Qaraqosh, Iraq, November 2016 Conflict Armament Research

Fast jet crews, Dr Lee argued, were “valorised in the media as ‘brave’, ‘courageous’, ‘heroes’”, but drone operators had yet to receive the public recognition they deserved for risking their mental health.

“The subject of medals and awards for Reaper personnel should be revisited as a matter of urgency,” he said. “These would not be for conventional acts of gallantry in the face of enemy fire but for meritorious service that has significant tactical or operational impact and which incurs significant mental and social costs to the personnel and families involved.”

During the course of his research, Dr Lee, a former RAF chaplain who is now a reader in Politics and Ethics at Portsmouth, found that despite sitting in converted shipping containers 2,000 miles from the killing zones, drone crews did understand the impact of their actions.

One drone pilot told him: “We may watch target A for weeks. What we also see is the individual interacting with his family – playing with his kids and helping his wife around the compound.

“When a strike goes in we stay on station and see the reactions of the wife and kids when the body is brought to them.

"You see someone fall to the floor and sob so hard their body is convulsing.”

Dr Lee added that among drone crews “a small number of individuals experience clear mental trauma, and PTSD cases have been identified.

“At the other end of the spectrum, a small number of individuals appear able to efficiently compartmentalise the killing process.

“The majority sit between those two positions – willing to fire weapons where necessary and for the most part ‘just doing my job.’”

One Reaper sensor operator, who guides the missile onto the target, told him that Isis atrocities like executing gay men for being gay meant that in terms of moral concerns about taking an opponent’s life, Isis jihadists were “the easiest enemy I will ever fight”.

But, Dr Lee said, many drone operators were frustrated at their inability to justify their work in public, with one telling him: “When the Ministry of Defence speaks the truth that we don’t kill civilians, that immediately is assumed to be a lie by those whose mantra is unable to accept the paradigm shift that we genuinely don’t kill non-combatants.”

This frustration, said Dr Lee, was “compounded by the lack of legitimation that would come from medallic or other official recognition.

“Physical risk and physical harm in the line of duty is still considered heroic. Mental health risk and harm, on the other hand, is not taken as seriously.”

Between October 2014 and June 30 2017, RAF Reaper drones, which carry up to four Hellfire missiles and two Paveway II 500lb bombs, are thought to have flown 2,035 missions over Iraq and Syria, firing a total of 726 weapons.

In August 2015 Cardiff-born Reyaad Khan and Ruhul Amin from Aberdeen were killed by the RAF in what was described as the first targeted UK drone attack on a British citizen.

David Cameron justified the attack by saying Khan – the target of the drone operation – had been plotting “barbaric” attacks on UK soil.

The RAF says drone operations over Iraq and Syria have not led to known civilian casualties.

RAF drone operators are expected to work to a “zero civilian casualties” policy stricter than the Geneva Conventions, which permitted killing (though not deliberate targeting) civilians, provided the numbers involved were not “excessive in relation to the concrete and direct military advantage.”

The RAF rules were introduced after a British-operated drone mistakenly killed four civilians in Helmand, Afghanistan in 2011.

Chris Cole, director of the Drone Wars pressure group said: “Drone pilots do horrible things, but they are following orders.

“Debating whether they are heroes or psychopaths is a distraction from the real issue, which is that drones lower the threshold for the use of force.

“’The ultimate in sanitised warfare’ is an accurate description. Drones take away the political cost of sending troops overseas to intervene in conflicts.

“They make it much easier for politicians to go for the short-term ‘take out the bad guys’ option, instead of seeking the long-term diplomatic and political solutions needed to deal with the underlying causes of conflicts.”

US Central Command has admitted that air strikes by coalition forces have killed at least 484 civilians in Iraq and Syria, and Mr Cole questioned whether the RAF was correct to say that there have been no fatalities from British drone operations.