The British diplomat Robert Ford, who has died aged 90, was captured by communist troops in Tibet in 1950 and spent five years being re-educated. Michael Bristow looks back at this pivotal moment in his life.
On the day he was released by the Chinese, Mr Ford was taken to the border with Hong Kong, then still a British colony, and told to walk across the rickety railway bridge that then separated the two territories - and divided the worlds of communism and capitalism.
"I wondered whether I would get across the bridge - I didn't know whether I would get a bullet in my back," is how Mr Ford remembered that final, stressful journey to freedom.
He did get across the bridge, and went on to forge a new career as a British diplomat. But the fear, loneliness and uncertainly of being re-educated by Chinese communist interrogators stayed with him for the rest of his life.
Caught while escaping
Robert Ford was born in Staffordshire in 1923. He served in the air force during World War II and at the end found himself in India, teaching Indian army officers how to be radio operators in Hyderabad.
He was bored with his job and so when an exciting opportunity came up, he jumped at it. He got the chance to go to Tibet to be a radio operator in the British mission in Lhasa. He enjoyed it so much that a little later he applied to do a similar job for the Tibetan government.
Tibet is now a fully integrated part of China, but when Mr Ford made his slow way into the Himalayan territory in 1948 to work for the Tibetans, they were mostly free to manage their own affairs. China was then in the middle of a civil war and had no way of enforcing its claim that Tibet is part of the Chinese nation.
Mr Ford was eventually sent by the Tibetan authorities on a long pony ride to the eastern town of Chamdo, where he set up and maintained a radio link with Lhasa. It was close to Chinese-controlled territory. Too close, as it turned out.
The Chinese communists won the civil war in 1949 and in October the following year decided to press their claim to Tibet by invading with a small force.
Mr Ford left his escape to Lhasa too late and was eventually caught by Chinese troops as he sheltered in a monastery with a group of Tibetan officials, who had decided to surrender rather than fight.
For Mr Ford, it was the start of five years that were to test his beliefs to the very core.
Initially, the radio operator thought that the Chinese would sooner or later realise that he was innocent.
"I suppose I was very English in that regard. I could understand that the Chinese communists wouldn't like what I'd been doing, working for the Tibetan government. But I didn't feel guilty in the sense that I'd done something wrong," he said in an interview with the BBC shortly before he died.
But the Chinese kept up their questioning, always implying that Mr Ford was guilty. It seemed they thought they had captured a spy and, little by little, Mr Ford came to see that his position was not as good as he had first thought.
He faced charges of spreading anti-communist propaganda, exploiting the people by being a Tibetan official and helping the Tibetans resist the communist troops.
They were charges that could have led to the death penalty so, reluctantly, the British prisoner realised he would have to confess to something, even though he would have to tell degrading lies about himself.
But the communists were not happy with a simple confession. Re-education is about turning a criminal into a new person, so Mr Ford's admission of guilt was only the start of a process; his Chinese interrogators wanted him not just to admit to his guilt, but to believe that he had done wrong as well.
This is how he put it in the book he wrote about his experiences shortly after being set free.
"It was no good just saying Stalin and Mao [Zedong] were right - that would have been an impertinence. I had to apply their general wisdom to my own particular problem, showing that I was now seeing my crimes from the correct political standpoint," he wrote.
There were endless study sessions among the prisoners and their guards. Cellmates even had to continue their discussions about Marxist theory when they were locked up for the night.
And then something unexpected happened to the man who had grown up not really questioning the British view of the world: he started to doubt what he had previously believed to be unshakeable truths.
At first he thought he could merely parrot the correct political statements, but then he found that, on some level, he was starting to believe the propaganda he was forced to say in the fluent Chinese he acquired while in prison.
Brainwashing ebbed away
At group meetings he wanted to join in and was sometimes overtaken with the mass emotion the prisoners showed for their faith in communism and Mao's new hopeful nation. "The diabolical cleverness of thought reform is that the victim is made to want to believe," he wrote in his book.
But the interrogators never completely conquered their prisoner, as was revealed by the British man's thinking when given the chance to write home to his parents.
Despite the re-education, he wanted to write a reassuring note, but knew that his captors would read it and look for evidence that he had genuinely been reformed.
Mr Ford resolved his problem by writing a few short sentences revealing that he was all right at the beginning and end of the letter, with the long middle section reserved for "pro-China propaganda". "My mother was very astute and picked this up," he said.
And then, suddenly, in 1954 a chain of events began that led to Mr Ford's release.
He was tried and found guilty of, among other crimes, spying, and sentenced to 10 years in jail. Almost immediately afterwards he was told he would be deported, although he was not finally set free into Hong Kong until the following year.
His brainwashing gradually ebbed away, but the man who became a diplomat and served all over the world, in Angola, Indonesia and Geneva, never forgot his time in a communist prison.
"It changed me. I had a whole different outlook on what life was about and what was important," he told the BBC, although he admitted that it was initially a struggle to return to who he had been before his capture.
"The beliefs that you have before are strengthened, but there are also the doubts that you've been inculcated with. These have to be overcome."