DJ: Michael, as an historian, you've looked perhaps more than anyone else into the culture of terrorism, the world from which these people come, the intersection between terrorism and politics, business or crime. And terrorism has a long history of attacking symbols of capitalism, the most obvious one is 9/11 but one thinks also of the kidnappings of the Baader-Meinhof or the Red Brigades back in the 1970s.

Michael Burleigh: The bombings in Canary Wharf and the City by the IRA.

DJ: The IRA, too, deliberately targeted businesses. There's a whole history of this before we even get onto things like piracy, which you've also written about. How do you see all this?

MB: What Luke is primarily concerned with are attempts to intimidate businesses, to interfere with rights of free speech through interdicting things like this book. But also it's been going on in lots of other countries, in Algeria where they murdered novelists for writing books they didn't like, and lots of journalists were murdered in the early '90s by Islamists.

Luke quite rightly draws attention to animal rights fanatics who are essentially trying to inhibit the right of scientists to engage freely in certain types of research - there are ethical conventions that scientists themselves have drawn up. But I don't think that's actually really typical of the more sinister types of racket that terrorists have been involved in. Ethno-nationalist terrorism, which is deeply embedded in particular communities, is more typical. I'm thinking of Sinn Fein-IRA in Northern Ireland and organisations like Eta in Spain, where there's a much more organised crime-type, very regular, deep-seated and long term form of extortion going on. It can literally range from deciding you're short of funds on a Friday night, so let's go and stiff the butcher, to much more sinister things where for a time Sinn Fein-IRA got a lock on the Irish building trade. It's like a cancer that got into the entire UK construction industry, and they controlled the supplies of labour and raw materials. One up from that are the very sophisticated insurance frauds - the levels of insurance fiddles going on in Northern Ireland were quite phenomenal. When half-a-dozen of their nags went off a cliff because they were scared by army helicopters, farmers would say that these were all prize geldings, and people would testify to this.

And you've certainly got this going on all over the Basque country, where the terrorists are very closely connected to the community, and they just routinely take protection money. And they've done it on the other side of the Spanish-French border: they drove the restaurateur Alain Ducasse out of the region because they thought he was parodying their
native cuisine, so they bombed his resort near Biarritz.