Only a year after the Maidan protests swept a pro-Western government into power, Kiev's new regime is in danger of collapsing among endemic corruption, a leading security analyst said.
Mark Galeotti, clinical professor of global affairs at New York University, has advised bodies including the Foreign Office and Interpol, and has spent more than three decades researching the corrosive networks of criminality and corruption in eastern Europe.
He said unless Kiev makes serious efforts to purge the country of corruption, urgent international financial assistance would dry up and popular support for the new government could collapse.
"The frustrations that led to Maidan have not been resolved," Galleotti said. "There is a lot of frustrated potential floating around. With all this potential there is the risk that very quickly some new force could cohere and arise."
He raised the spectre of an uprising led by an "ultranationalist populist". He said: "There are a lot of nasty wellspring from which water could be drawn."
Meanwhile, Ukraine Finance Minister Natalie Jaresko had previously warned the country faces a "serious, serious financial crisis", with its GDP shrinking by 7% in 2014 and its war-battered economy in ruins.
Disillusion issues to solve
Transparency International's Corruption Perceptions Index rates Ukraine 142nd in the world, alongside Uganda, and behind Russia.
Galeotti said the "momentary honeymoon" of goodwill after the revolution, which could have generated an effective purge of corrupt officials and bodies, had dispersed.
"You have a genuine disillusion that has set in in a lot of parts of Ukraine because they have got all the hardships with none of the benefits, and you have the same corrupt figures who have been able to reinvent themselves," he said.
Galeotti said that with President Petro Poroshenko's attention focused on the gruelling conflict in east Ukraine with Russia-backed rebels, the government was failing to act.
Popular rage at corruption is believed to have fuelled not just the 2014 Maidan protests, which swept the pro-Moscow government of Viktor Yanukovych from power, but also the 2004 Orange Revolution. But Galeotti warned a new network of officials was simply grafting itself on to the old network of corruption.
Galleotti pointed out that after Maidan, Ukraine "might have a government that represents the will of the people more directly, but structurally Ukraine is the same country as it was before Yanukovich fell".
He said: "To tackle the organised crime problem, Kiev is going to have to declare war on a significant section of its own elite, and in particular local elites who are the people who basically run the country for Kiev. I think that will be an incredibly brave act, and one thing about Poroshenko is that he is not really the man to do brave, dangerous deeds, he wants to be loved."
Financial aid gives Ukraine helping hand
In February, Ukraine received a $40bn (£27bn, €37bn) bailout package from the international community. Recently, billionaire and philanthropist George Soros announced he would personally donate $1bn in financial aid to the country, in a bid to raise a further $50bn in aid.
Jaresko announced in a speech in Washington DC in March that tackling corruption would be one of the government's core objectives in the fight to "create conditions for the return of economic growth and prosperity".
But Galleotti said there were no signs of serious action and without an anti-corruption purge, much of the money would be wasted.
"Given that Ukraine is more corrupt than Russia, there is a disinclination to give money which will simply end up in the Cayman Islands or Switzerland," he alleged. "If people were to pay the amount he demanded, that would simply be a massive bonanza for the crooks and embezzlers."
In the wake of Maidan, stashes of artworks were found in the palatial home of Yanukovich and billions are believed to be laundered through complex series of offshore accounts and shell businesses.
Galeotti said tearing up deeply rooted networks of corruption would be difficult and urged greater pressure on Kiev from the EU, warning that without it sustainable democracy in Ukraine may prove impossible.
He said: "Reform is going to be painful, there is no way around that. It means challenging the elite, challenging the way things are run, a lot of people in the short term their lives will get harder, if you simply provide money, then Ukraine has that much less reason to change. That is why Soros, for all the best reasons, was entirely wrong."