LAST week an Austrian judge snubbed American prosecutors by refusing to extradite Dmitry Firtash, a Ukrainian oligarch whom they had charged with bribery. Mr Firtash, the reclusive son of a truck driver and an accountant, made his fortune as a middleman helping sell Russian and Central Asian gas to Ukraine. He became a political kingmaker during the presidency of Viktor Yanukovych (pictured at left, with Mr Firtash, at the opening of one of Mr Firtash's factories). In March 2014, after Mr Yanukovych was ousted by the Maidan revolution, Mr Firtash was arrested in Vienna at the behest of America's Federal Bureau of Investigation. He claims that his real offence was to get in the way of American interests in Ukraine. The Austrian judge agreed, ruling that the American charges were “politically motivated". The decision exposed the limits of American influence in Europe, and offered a reminder that Ukraine’s disarray is not a simple tale of Russian aggression, but also the result of its homegrown demons.

Mr Firtash has long been of interest to American law enforcement. His gas company RosUkrEnergo, which he co-owned with Russia's Gazprom, was seen as a means for the Kremlin to influence Kiev's politics—until Yulia Tymoshenko, then prime minister, cut him out of the business. He allegedly had ties to Semyon Mogilevich, a notorious Russian organised-crime boss. American prosecutors say that Mr Firtash and his associates paid Indian officials $18.5m in bribes to help close a titanium-mining deal. (Mr Firtash's business empire included a large titanium-dioxide manufacturing operation.) In his defence, Mr Firtash cast himself as a victim of Western geopolitical intrigue. Defence lawyers linked his arrest with the comings and goings of Victoria Nuland, an American assistant secretary of state. The judge noted that the evidence of bribery in India provided by the Americans was minimal compared with the political interests at stake.

To bolster the claim that America wanted him sidelined, Mr Firtash boasted of his influence in Ukrainian politics. Last spring, he recounted, he arranged a summit in Vienna between two prospective presidential candidates: Vitaly Klitschko, the champion boxer turned politician, and Petro Poroshenko, the so-called "Chocolate King". After the meeting, Mr Klitschko withdrew from the race, opting instead to become mayor of Kiev and clearing Mr Poroshenko's path to the presidency. Mr Klitschko's political party later became the foundation for Mr Poroshenko's parliamentary faction. "We achieved what we wanted: Poroshenko became president, and Klitschko became mayor," Mr Firtash said. Both Mr Klitschko's and Mr Poroshenko's camps reject Mr Firtash's claim to have brokered a deal for the presidency. Yuriy Lutsenko, head of Mr Poroshenko's party, calls Mr Firtash's defence the reaction of a "cornered predator".

Although Mr Firtash may be cornered, he appears determined to stay in the ring. He has remained active in Vienna, where he has been free since a week after his arrest after posting bail of $125m (allegedly paid by a Russian billionaire close to Vladimir Putin's inner circle). In March 2015 he launched the Agency for Modernisation of Ukraine, holding an international conference in Vienna that attracted British, French and German business figures. Mr Firtash's long-time partner, Sergei Levochkin, is one of the leaders of the Opposition Bloc party, a successor to Mr Yanukovych's Party of Regions. Opposition Bloc has been positioning itself for a comeback in local elections this autumn, campaigning against unpopular austerity measures demanded by Western donors.

Mr Firtash may not rush back to Ukraine, and he will find himself a severely diminished figure when he does return. Ukraine's new authorities have been slowly dismantling his empire. New laws governing the natural-gas market will curb the influence of oligarchs. The government recently confiscated some 500m cubic metres of gas belonging to Ostchem, one of Mr Firtash's companies. Ukrainian prosecutors have announced charges of their own against Mr Firtash, and the interior ministry has indicated a willingness to cooperate with American investigators.

The crackdown against Mr Firtash is part of Mr Poroshenko's crusade to "de-oligarchise" the country. That is a fraught process: Mr Poroshenko's ability to change Ukraine's social contract is undermined by his own history of oligarchic dealing. He promised during the presidential campaign to make a break with the past by selling off his own business assets, which include the confectionery company Roshen. He has not, and indeed his income rose in 2014, while Ukraine's economy contracted. Ukrainians have taken note: across the country, citizens are sceptical of the president's intentions. At the headquarters of one pro-Maidan “self-defense" group in Odessa, a picture of Mr Poroshenko merged with a pig now hangs on the fridge. The Maidan was supposed to be a revolution against an oligarchic system, not a movement to punish a gas oligarch and reward a chocolate one.