IT’S 9.30AM IN MINNEAPOLIS. The bridge over the Mississippi that used to take Taner Akçam to work won’t be rebuilt for a year, but that’s not what’s vexing him. His problem is the Turkish Secret Service.

Professor Akçam is a Turk and an historian. In 1999, 84 years after the event, he completed a harrowing doorstop of a book on the Armenian genocide – densely factual and unsparing of the Turkish culprits – now published in English. As a result, he is being hounded from Istanbul to his Midwestern academic exile by ultranationalists from his home-land . . . and by spooks.

That’s his theory, anyway. How else to explain what happened in Montreal in February when he was detained by airport police who said that they had grounds to suspect he was a terrorist. Those grounds turned out to be hostile postings on amazon. com and his own Wikipedia page, doctored by people who had also, apparently, not only alerted precisely the airport personnel who would be handling Akçam’s flight, but also had information on the historian’s past, including a 1974 arrest for protesting at Turkey’s invasion of northern Cyprus, that had never had been in the media.

So who gave the tip-off? Akçam laughs wearily. He doesn’t know. “But my arrival was known of by the Turkish consul. He was even invited to my lecture.”

There might be something comical about this Wiki-assisted harassment – except that two weeks earlier, Akçam’s friend and fellow intellectual, the Turkish-Armenian newspaper editor Hrant Dink, was murdered in broad daylight on an Istanbul street. His crime, like Akçam, was to have used the “G-word” to refer to the state-sponsored murder of between 300,000 and 1.3 million Anatolian Armenians in 1915 with the term reserved by the 1948 UN convention on genocide.

Akçam foretold his friend’s death to his face a few days earlier. They were in Istanbul, chatting about a presidential campaign that was fuelling tensions between nationalists and liberals. “I told Hrant there would be political assassinations,” Akçam remembers. “And I told him, ‘Hrant, if I made a list of the people who will be assassinated I would put you No 1. Please leave Turkey, at least until the end of the election.’ He didn’t want to. He was, I think, expecting his death.”

For his own part, even in Minneapolis, even after 30 years of opposition to Turkey’s denial of responsibility for the genocide, Akçam says he has never been as scared as he is now.

Next week he travels to the Edinburgh Book Festival to talk about the the fight for freedom of expression. The prospect of travel is hardly soothing, “but I have to do it because it is what they want us not to do. They want us to shut up and sit down.”

He is not talking about Turkey’s elected government, but the unelected military and bureaucratic hierarchies he blames for a “culture of hatred and animosity” towards an honest reckoning with the past.

He says that he feels that hatred whenever he returns to Istanbul, which is about once a year. Once spotted by the nationalist press, the vilification starts swiftly. He is branded a traitor, a foreign agent and a liar, even though he is the only Turkish historian to have based his analysis of 1915 on official Ottoman documents.

“On the second or third day you get the feeling that you should not be showing yourself much in public.”

Small wonder that of his fellow historians inside Turkey, almost none are actively researching topics related to the Armenian question.

This is Turkey, a nation three years ago accepted as a candidate for EU accession and which could be a member by 2015. Shouldn’t it show that it can uphold the most basic democratic freedoms and then reapply?

Absolutely not, says Akçam. For the EU to go cold on Turkish membership now would be to set the country on “the path to authoritarianism”. Membership offers the only hope of cutting down the unelected hierarchies and ending official denials.

Seven years ago, Professor Akçam sued his critics for libel for calling him a German spy. In January, he lost on appeal. “So the ultimate decision from the judiciary is that it is the right of everybody to accuse me of being on the payroll of the German government because I am using the genocide term. This is outrageous. You cannot criminalise talking about history. It is unbelievable.” And, for a man whose only crime was to brave his country’s archives, very frightening.

A SHAMEFUL ACT: The Armenian Genocide and the Question of Turkish Responsibility by Taner Akçam

Constable and Robinson, £9.99; 600pp

Buy the book here at the offer price of £8.99 (free p&p)

Taner Akçam is at the at Edinburgh International Book Festival on Monday August 27 at 11am. Call 0845 3735888 www.edbookfest.co.uk

Times Recommends

• The Sunday Times 100 best holiday reads
• What will we be reading this summer: the booksellers predict
• Literary festivals: a survivor’s guide