Written by Murat Kurnaz for The New York Times

I LEFT Guantánamo Bay much as I had arrived almost five years earlier – shackled hand-to-waist, waist-to-ankles, and ankles to a bolt on the airplane floor. My ears and eyes were goggled, my head hooded, and even though I was the only detainee on the flight this time, I was drugged and guarded by at least 10 soldiers. This time though, my jumpsuit was American denim rather than Guantánamo orange. I later learned that my C-17 military flight from Guantánamo to Ramstein Air Base in my home country, Germany, cost more than $1 million.

When we landed, the American officers unshackled me before they handed me over to a delegation of German officials. The American officer offered to re-shackle my wrists with a fresh, plastic pair. But the commanding German officer strongly refused: “He has committed no crime; here, he is a free man.”

I was not a strong secondary school student in Bremen, but I remember learning that after World War II, the Americans insisted on a trial for war criminals at Nuremberg, and that event helped turn Germany into a democratic country. Strange, I thought, as I stood on the tarmac watching the Germans teach the Americans a basic lesson about the rule of law.

How did I arrive at this point? This Wednesday is the 10th anniversary of the opening of the detention camp at the American naval base at Guantánamo Bay, Cuba. I am not a terrorist. I have never been a member of Al Qaeda or supported them. I don’t even understand their ideas. I am the son of Turkish immigrants who came to Germany in search of work. My father has worked for years in a Mercedes factory. In 2001, when I was 18, I married a devout Turkish woman and wanted to learn more about Islam and to lead a better life. I did not have much money. Some of the elders in my town suggested I travel to Pakistan to learn to study the Koran with a religious group there.

I made my plans just before 9/11. I was 19 then and was naïve and did not think war in Afghanistan would have anything to do with Pakistan or my trip there. So I went ahead with my trip.

I was in Pakistan, on a public bus on my way to the airport to return to Germany when the police stopped the bus I was riding in. I was the only non-Pakistani on the bus – some people joke that my reddish hair makes me look Irish – so the police asked me to step off to look at my papers and ask some questions. German journalists told me the same thing happened to them. I was not a journalist, but a tourist, I explained. The police detained me but promised they would soon let me go to the airport. After a few days, the Pakistanis turned me over to American officials. At this point, I was relieved to be in American hands; Americans, I thought, would treat me fairly.

I later learned the United States paid a $3,000 bounty for me. I didn’t know it at the time, but apparently the United States distributed thousands of fliers all over Afghanistan, promising that people who turned over Taliban or Qaeda suspects would, in the words of one flier, get “enough money to take care of your family, your village, your tribe for the rest of your life.” A great number of men wound up in Guantánamo as a result.

I was taken to Kandahar, in Afghanistan, where American interrogators asked me the same questions for several weeks: Where is Osama bin Laden? Was I with Al Qaeda? No, I told them, I was not with Al Qaeda. No, I had no idea where bin Laden was. I begged the interrogators to please call Germany and find out who I was. During their interrogations, they dunked my head under water and punched me in the stomach; they don’t call this waterboarding but it amounts to the same thing. I was sure I would drown.

At one point, I was chained to the ceiling of a building and hung by my hands for days. A doctor sometimes checked if I was O.K.; then I would be strung up again. The pain was unbearable.

After about two months in Kandahar, I was transferred to Guantánamo. There were more beatings, endless solitary confinement, freezing temperatures and extreme heat, days of forced sleeplessness. The interrogations continued always with the same questions. I told my story over and over – my name, my family, why I was in Pakistan. Nothing I said satisfied them. I realized my interrogators were not interested in the truth.

Despite all this, I looked for ways to feel human. I have always loved animals. I started hiding a piece of bread from my meals and feeding the iguanas that came to the fence. When officials discovered this, I was punished with 30 days in isolation and darkness.

I remained confused on basic questions: why was I here? With all its money and intelligence, the United States could not honestly believe I was Al Qaeda, could they?

After two and a half years at Guantánamo, in 2004, I was brought before what officials called a Combatant Status Review Tribunal, at which a military officer said I was an “enemy combatant” because a German friend had engaged in a suicide bombing in 2003 – after I was already at Guantánamo. I couldn’t believe my friend had done anything so crazy but, if he had, I didn’t know anything about it.

A couple of weeks later, I was told I had a visit from a lawyer. They took me to a special cell and in walked an American law professor, Baher Azmy. I didn’t believe he was a real lawyer at first; interrogators often lied to us and tried to trick us. But Mr. Azmy had a note written in Turkish which he had gotten from my mother, and that made me trust him. (My mother found a lawyer in my hometown in Germany who heard that lawyers at the Center for Constitutional Rights represented Guantánamo detainees; the center assigned Mr. Azmy my case.) He did not believe the evidence against me and quickly discovered that my “suicide bomber” friend was, in fact, alive and well in Germany.

Mr. Azmy, my mother and my German lawyer helped pressure the German government to secure my release. Recently, Mr. Azmy made public a number of American and German intelligence documents from 2002 to 2004 that showed both countries suspected I was innocent. One of the documents said American military guards thought I was dangerous because I had prayed during the American national anthem.

Now, five years after my release, I am trying to put my terrible memories behind me. I have remarried and have a beautiful baby daughter. Still, it is hard not to think about my time at Guantánamo and to wonder how it is possible that a democratic government can detain people in intolerable conditions and without a fair trial.