In the 1970s a group of young people were jailed for murderous IRA bombings they did not commit. Their case has important lessons for us now as we face new terrorist threats.
Donald Trump says he hates the "politically correct" fight against Islamic Terror. When he's President he promises to strip terror suspects of their human rights, target their families and authorise waterboarding and "go far, far beyond it" i.e. more torture.
The rise of Trump is a depressing spectacle for most of us. But for one 61 year old man, formerly of Belfast but now living quietly in Washington DC, it has a particular dread.
In 1974, Paul Hill was a happy go lucky 19 year old living among London's Irish community. He'd left his native Belfast to escape "The Troubles".
The IRA launched a ruthless bombing campaign, including blowing up crowded pubs in Guildford and Woolwich, killing and maiming ordinary people.
Paul was vaguely aware of this from the newspapers and TV but he was busy, searching out work on building sites and planning a life with his pregnant girlfriend.
To counter public and press outage at the bombings, the then Home Secretary introduced temporary and, in his own words, draconian powers to help catch the perpetrators. Police could now question suspects for up to seven days without charge.
Paul was the first man held under these new powers. He was taken to Guildford Police Station and, after seven days, he had signed confessions to his involvement in three pub bombings and eight murders. He implicated Irish friends and acquaintances in the attacks.
At the trial of the Guildford Four, Paul and his co-accused pleaded innocent but were found guilty. Paul was handed down what was the longest sentence ever given in a British court. The judge's only regret was he couldn't hang him.
The only evidence against Paul and his co-accused were the confessions they signed. There was no other evidence.
In fact the forensics pointed to the Four's innocence, but this was concealed from the court. Witnesses who gave alibis for some of the Four, including Paul, were bullied into changing their statements.
An IRA active service unit were arrested soon after the Guildford Four trial. This gang stood up in court and told the judge the Guildford Four were totally innocent and they had carried out the Guildford and Woolwich bombings.
But it would take a 15 year campaign, supported by Law Lords, former Home Secretaries, MPs like Tony Benn and Jeremy Corbyn, bishops, cardinals, US Senators and even Mikhail Gorbachev, before the Four would see their convictions quashed and them released.
The appeal court in 1989 found police had seriously misled the court in the original trial and lied under oath. This miscarriage of justice made headlines around the world and dragged the reputation of British justice through the mud.
The dictionary definition of torture is any act by which severe pain or suffering, whether physical or mental, is intentionally inflicted on a person.
In interrogations, Paul says he was subjected to mock executions, with loaded guns put to his head. He was beaten and brutalised, kept naked and denied sleep or food for days. He was forced to drink water out of the toilet. He was hung out of windows two storeys up. He was told he'd be murdered and his body dumped in an alley.
Threats were made against his family in Belfast. Paul was told his pregnant girlfriend would be arrested and charged if he didn't start talking.
Think what you might confess to if someone did that to you.
The case against torture is not one about political correctness. Torture simply doesn't work.
Ali Soufan, a one time FBI special agent with experience interrogating al-Qaeda operatives, says: "When they are in pain, people will say anything to get the pain to stop. Most of the time, they will lie, make up anything to make you stop hurting them. That means the information you're getting is useless."
The information gleaned from Paul and the other members of the Guildford Four was indeed useless. Sadly it took 15 years for the world to recognise that.
In my new play Your Ever Loving I've taken letters Paul wrote to his family from prison and transcripts from the trial and appeals to bring this story to life.
Hopefully the drama brings home to audiences the destruction wrought when we turn a collective blind eye to torture, not only to innocent people's lives but to our faith in our justice system.
Paul's built a new life in the States. But 27 years on from his release, he still suffers nightmares and bouts of depression. Watching Trump on the TV news doesn't help.
"I took some comfort from the thought that my misfortune would lessen the possibility of it happening to others," he says. "It would appear nothing has been gleaned from these miscarriages of justice, especially those with political overtones."
Your Ever Loving opens at N16 Theatre, Balham, London on 18th April and runs until 5th May. theatren16.co.uk
It transfers to the Alphabetti Theatre, Newcastle, for a short run, 11th to 14th May. alphabettitheatre.co.uk