On Wednesday, the new President of the United States stated that he believes torture “absolutely” works and that the US should “fight fire with fire.” Trump is wrong. Torture is illegal, immoral and ineffective. When our Prime Minister meets with the President, she would be well-advised to remind him of this.

During George W. Bush’s presidency, and particularly following the 9/11 attacks, the US government frequently made use of torture techniques to gather intelligence on suspected terrorism. The Bush Administration was less candid than Trump choosing to mask its use of torture with euphemisms such as “enhanced interrogation”. But it was undoubtedly torture. Suspects were, for instance, beaten, deprived of sleep to the point of hallucination, repeatedly slapped, waterboarded and sexually humiliated.

Following the election of Barack Obama and the end of the Bush Administration, the US Senate Select Committee on Intelligence compiled a bipartisan evaluation of the use of enhanced interrogation under Bush. The report concluded that the use of “enhanced interrogation techniques” was not effective. It produced no actionable intelligence that had not already been collected with conventional methods that did not involve torture. Partly in response to this report, the US Congress then passed an anti-torture law which created minimum standards for the tactics used to question detainees and allows the International Red Cross access to terrorism suspects held in US custody

But the use of torture is not just ineffective. It actively damages intelligence agencies’ ability to gather information and creates resentment against the countries which use it. Torture frequently produces false information. A victim of torture is likely to tell their interrogator anything to end the torture. Because the victim is repeatedly being asked for information, they will give the interrogator what they want, whether it is true or not. This can lead intelligence agencies on wild goose chases which consume valuable time and resources.

Torture also comes at the cost of resentment. Guantanamo Bay – the great symbol of US  sanctioned torture – features repeatedly in Jihadist literature. Extremists weave America’s use of torture into a broader story of Muslims being unfairly imprisoned and under attack by the West. This makes torture a recruitment tool for the West’s enemies.

It is still possible that saner heads will prevail and the US will not resume its use of torture. It is encouraging that Trump’s Secretary of State for Defense, James Mattis, has expressed his view that torture doesn’t work.

But if the US does resume its use of torture, then the UK will be placed in a very difficult position. The US and UK intelligence agencies have some of the closest relations of any intelligence agencies in the world. They regularly perform joint-operations and share intelligence. But under international agreements, British intelligence agencies are required to leave the room if torture is taking place and must refuse to use evidence which is gained through torture. These requirements allegedly caused a CIA station chief during the Bush Administration to describe MI6 officials as “wimps”.

In practise, determining whether intelligence was procured using torture is very difficult and the UK regularly makes use of evidence gained by countries known to use torture, such as Saudi Arabia. But the UK government would risk legal action and a political scandal if it was found to be complicit in any use of torture by the Trump Administration.

May would be best advised to simply tell Trump that torture does not work. If the Prime Minister could succeed then it would be a great victory not just for the innocent victims of torture but for America’s reputation abroad.

James Dobson works at Bright Blue.