Andrew Mitchell is a former International Development Secretary, and is MP for Sutton Coldfield.

Having served this country as an officer in the Royal Tank Regiment, and as a Cabinet minister on the National Security Council, I understand that Britain’s security interests depend on a strong relationship with the United States of America.

But that relationship should be an honest partnership based on a bedrock of shared values. It is dangerously undermined when our politicians allow those values to be compromised – when, in the words of Benjamin Franklin, we “give up essential liberty, to purchase a little temporary safety”.

As a member of the Conservative shadow cabinet when the last Labour Government was in power, I watched as the UK was mixed up in a host of Bush Administration abuses – abuses like the torture and rendition of Abdul Hakim Belhaj and Fatima Boudchar, a Libyan dissident and his pregnant wife, for which Theresa May rightly apologised earlier this year.

It is vital that we learn the lessons of the failed “war on terror”, and realise that our critical security partnership with the US does not require us to embrace every whim of its leaders – including when they suggest publicly that “torture works”.

Recent developments across the Atlantic make these lessons all the more important.

Last week, a court case in the United States compelled the CIA to release classified cables describing acts of torture inflicted in a secret CIA prison in Thailand in 2002. The cables were reportedly written or authorised by the now-CIA Director, Gina Haspel, and describe how CIA interrogators talked of torture as like “tenderising a fine steak”.

These cables reveal how one prisoner had his clothes ripped off him and was forced to remain naked for prolonged periods. He was made to move between a coffin-sized box and another which compelled him to curl up in a ball, where he was locked for hours on end. He was subjected to a mock killing by supposed ‘rogue agents’ who pretended to abduct him from his cell while hooded.

The cables also describe the use of waterboarding: effectively pouring water over a prisoner’s cloth-covered face to induce terrifying temporary drowning. The pain and panic this induced quite clearly constituted torture.

Of course, these immoral and illegal acts achieved absolutely nothing. An individual being tortured in this way will tell you anything to stop the suffering, irrespective of veracity, and these false leads waste precious time that should be spent investigating real threats.

Sure enough, the US Senate later noted that these acts of torture produced “no actionable intelligence” whatsoever.

Torture is not simply ineffective. It also undermines the values which generations of British service personnel have risked their lives to protect. After the destruction of the Second World War and the horrors of the holocaust, our country helped build a rules-based international system centred around justice and human rights. That system categorically rejects torture in its spirit and its laws.

If we turn our back on this system, the consequences will be grave. International prohibitions on torture protect British servicemen and women who are captured overseas, and eroding these rules puts them in greater danger when politicians place them in harm’s way. And how can our diplomats overseas urge progress on human rights issues when we are ourselves seen to be subjecting innocent people to abuses?

We are rightly proud of Britain’s international reputation for standing up against international thuggery and in support of universal values and human rights. But if we do not make a clean breast of Britain’s actions during this dark period that proud international reputation will be sullied and compromised.

Though the acts described in the CIA cables took place 16 years ago, we can’t simply assume that this will never happen again. Gina Haspel is now one of America’s most senior intelligence officials. She was appointed by a President who has endorsed “waterboarding…and a hell of a lot worse”.

What does this mean for British policy in 2018? First and foremost, we must be vigilant in monitoring US practices in such areas and refuse to be involved in operations where there is a risk of torture or arbitrary detention in legal black holes like Guantanamo Bay. Our security cooperation with the US has never been unconditional, and it is right and proper to ensure joint operations are subject to common sense safeguards.

We must also fully confront our past involvement in torture and rendition and be clear about what happened so that lessons for future are publicly acknowledged. As ever sunlight is the best disinfectant. While Parliament’s Intelligence and Security Committee recently published damning findings about past UK involvement in torture and rendition, Downing Street hamstrung the committee by preventing it from interviewing key witnesses, leading its highly-respected Chair, Dominic Grieve, to stress that his final report “must not be taken to be a comprehensive account”.

We must now complete the ISC’s account, and I have come to believe the best way to achieve this is through an independent judge-led inquiry which has the scope to explore all of the dark corners which the ISC could not. It would have been better for this inquiry to be concluded by the senior MPs whose judgement on the complex inter-play of human rights, politics, and stark reality would carry more conviction than that of a Judge. But given where we are, a judge-led inquiry is the best option.

Earlier this month I joined with a number of parliamentary colleagues who have served with distinction in our armed forces – David Davis, Crispin Blunt, Lord Ashdown and Dan Jarvis – to ask that the Prime Minister to launch such an inquiry.

As she returns from her summer break to this important decision, I hope she will realise that this is about learning the lessons of the past, so we can ensure we are protected in the future. In doing so we can continue our vital defence partnership with the United States while protecting UK personnel from complicity in torture and rendition – not least in an age of Trump and Haspel.