CITIZEN K

But how exactly did Khodorkovsky rustle up the money to start Russia's first commercial bank? Not long into his tenure as an oil mogul, Vladimir Petukhov, an outspoken critic of the new oligarchs and the mayor of Nefteyugansk - the town where Khodorkovsky's oil company, Yukos, was headquartered - was murdered. In the 1990s, Moscow was the murder capital of Europe. Khodorkovsky and the other oligarchs had private security details that were more like small combat army units.

"Your wild, wild West lasted decades," Khodorkovsky says to Gibney, an American. "Ours lasted only seven years."

Law and order was restored thanks to a corrupt understanding between the oligarchs and Boris Yeltsin, the first president of the Russian Federation, and later Putin. It's only when Khodorkovsky challenged Putin's authority that he found himself convicted for tax evasion, money laundering and embezzlement. Putin had used the situation as an opportunity to further strengthen his own power, and by the early 2000s all of the oligarchs either fled Russia or were arrested.

Gibney ('Enron: The Smartest Guys in the Room', 'Going Clear: Scientology and the Prison of Belief', 'Zero Days'), paces 'Citizen K' like a story written by Ian Fleming or John le Carré. As with Werner Herzog's interview with the last leader of the Soviet Union 'Meeting Gorbachev', one can question whether Gibney went too easy on his subject, but he does ask enough tough questions and Khodorkovsky is forthright, if somewhat vague, about his past misdeeds. Gibney is equally fascinated by Putin's journey from anonymous civil servant to strongman, and the broader political scene's increasing resemblance to performance art.

Speaking with a permanent sneer, Khodorkovsky insists that the years he spent in prison between 2005 and 2013 have made him a more thoughtful person. But it's impossible to say if his dissident activities from London, where he now lives with the millions he squirrelled away, are motivated by political consciousness or personal hate for Putin. The documentary supports him with a great cast of talking heads, including journalist Tatyana Lysova and former BBC journalist Martin Sixsmith.

'Citizen K' makes an interesting companion piece to Herzog's 'Meeting Gorbachev', which captured the promise of 1989 and mourned what came next. Gibney's documentary is essential viewing for anyone needing a history lesson about Russia since the fall of the Soviet Union, wants a frontline report on the current geopolitical landscape in Europe - including Ukraine - or just wants to know what it takes to bring down a towering political figure.