Nearly all western democracies, as well as dozens of other countries, have abandoned capital punishment. There is good reason for this: none of the arguments made in its favour stand up to scrutiny. It does not deter others, nor save innocent lives by ensuring that murderers cannot kill again. It is wrong to suggest there is a moral claim for retribution. The United States is an exception, wrongly persisting with the death penalty. So it is appalling to learn that a British cabinet minister would see fit to send two men to stand trial in America on charges that could see them executed.

Yet this is the chain of events that the home secretary, Sajid Javid, has set in motion with a letter to the US attorney general, Jeff Sessions, published in a newspaper on Monday. In it he states that the British government is prepared to waive its usual insistence that the death penalty should not be applied in the case of two men alleged to have been part of an Islamic State execution squad, Alexanda Kotey and El Shafee Elsheikh. They are being held by US-backed Syrian Democratic Forces, and appear likely to be tried in the US with the cooperation of the UK. The murders these men are alleged to have committed alongside two other British men – Mohammed Emwazi, known as Jihadi John, and Aine Davis – were barbaric. The victims included two British aid workers, Alan Henning and David Haines, as well as three Americans, the journalists James Foley and Steven Sotloff and humanitarian worker Peter Kassig. Other westerners were held hostage and tortured. It is not an exaggeration to say the videos that the killers made, in which their captives gave statements before being beheaded, shocked the world. No doubt some people will feel that the sheer horror of such deeds means we need not worry too much about due process. Emwazi was killed by a drone strike in Raqqa in 2015, while Davis is in prison in Turkey. Kotey and Elsheikh have been stripped of their British citizenship, and since the men they are alleged to have killed included Americans, there is a case for trying them in the US.

It’s not hard to see why this is Mr Javid’s preferred outcome. There is no doubt that dealing with the hundreds of British fighters for Islamic State is extremely challenging. But it is deeply concerning that Mr Javid apparently believes a successful prosecution is more likely to take place in the US than in the UK, even if this includes the violation of human rights norms to which the UK has adhered for decades. It is well known that such violations, and the existence of facilities such as Guantánamo Bay, can aid and facilitate terrorists. The UK government’s blanket opposition to the death penalty is a longstanding point of principle. Its abolition has been an objective of foreign policy. However heinous the crimes thought to have been committed by Kotey and Elsheikh, assurances that the death penalty would not be applied should have been sought from the US government in the usual way.