DONETSK, Ukraine — Most people here will tell you that the industrial heartland of Ukraine’s Russian-speaking east is no Crimea.

With a weaker separatist movement, a comparatively less enthusiastic pro-Russian population and no sign yet of the “little green men” — the mysterious Russian forces that seized the Black Sea peninsula last month and facilitated its secession — it seems unlikely this part of the country will fall to Moscow any time soon.

With tens of thousands of Russian troops massing on the border and American warnings about the possibility of an imminent invasion rising, nothing can be ruled out.

But even if Russian forces don't attack, that doesn’t mean Kyiv’s post-revolutionary government doesn’t have its work cut out here.

Rather than fending off military advances from Russia, observers say the new authorities will probably be faced with slow-simmering local discontent that will making taming the pro-Russian east difficult.

They say Ukraine’s post-revolutionary transition in this region will be long and hard, tinged by residual anger at Kyiv and calls for more regional power.

“I’m not an optimist,” says Oleksandr Klyuzhev, a political researcher in Donetsk. “I think we’re looking at months of sporadic calls for some sort of ‘separatism.’”

Despite recent fears that Russia would move into eastern Ukraine after annexing Crimea, the atmosphere in Donetsk — a bastion of industry and the center of ousted pro-Russian President Viktor Yanukovych’s support base — is not exactly insurrectionary.

After last weekend’s mass rally against the new Kyiv authorities, whom many here believe seized power in a “fascist” coup, a post-revolutionary calm has settled over the city’s wide, Soviet-era boulevards and tree-lined streets.

It helps that Ukraine’s security services have targeted some of the more radical separatists, having arrested the most prominent activist in the region on allegations of “extremism” after he proclaimed himself the “people’s governor” of the Donetsk region.

Leaders of other groups, many of which have since descended into infighting, have reportedly been forced to flee or gone into hiding.

But popular discontent remains prevalent, symbolized by a small tent encampment on Lenin Square, where pro-Russian groups hand out leaflets condemning the “chaos” on Kyiv’s Independence Square, the nerve center of the months-long demonstrations there.

Although marginal, those groups — including the Communist Party and a smattering of grassroots organizations — have nevertheless helped kindle pro-Russian sentiments here.

Experts estimate only around 30 percent of the population in Donetsk fully supports some form of integration with Russia.

But the low quality of life in this impoverished coal-mining basin, where industry has suffered since the collapse of the Soviet Union, means that such support — mostly from the area’s downtrodden working class — remains relatively steady.

Recent chatter has focused on the issue of “federalization,” a move supporters say would avoid Ukraine’s further break-up by appeasing pro-Russian citizens angry with the allegedly “nationalist” government they claim has failed to reach out to the east.

“The authorities aren’t reacting at all,” says Ivan Reyko, a Donetsk-based activist with the political party Russian Bloc, which advocates federalism. “No one’s coming out here and saying, ‘OK, let’s have a look at your proposal and we’ll figure something out.’”

Activists such as Reyko — who adds that he doesn’t support separatism and bemoans Crimea’s loss — say federalization would allow the region to exercise greater control over its political and economic life as well as promote the rights of Russian-speakers who often claim they face discrimination.

However, critics argue that federalization would be a slippery slope toward eventual secession because it provides the sort of institutional framework that the Kremlin easily exploited in Crimea.

Meanwhile, local officials — most of whom represent Yanukovych’s Party of Regions, which has been shaken by his ouster but remains the dominant political clan in eastern Ukraine — have been pressured by protesters into considering a referendum on the region’s status within Ukraine.

Elites here have voiced varying degrees of support for such a plebiscite, although it remains unclear exactly what the options would be or even how questions would be formulated.

Some, like Maxim Rovinsky, the communications chief for Donetsk’s city hall, express dismay that few understand the differences between “decentralization” — meaning the devolution of more authority to the region, something Prime Minister Arseniy Yatsneyuk has said he’d consider — and full-fledged “federalization.”

“Federalization is a bad example because Russia basically provided an inoculation against it” after its seizure of Crimea, he says. “But people are still voicing [support for] it on the streets.”

In any case, Ukraine’s prosecutor general blocked a decision earlier this month by the Donetsk regional legislature to hold any sort of regional referendum, arguing there’s no legal basis for such a move.

Despite the apparent loss of steam in the anti-Kyiv protest movement here, experts believe the Party of Regions may look to exploit the widespread anger to rebuild its local support.

“They will try to take all of these separatist or radically pro-Russian sentiments under control to use them as a bargaining chip against Kyiv,” says Klyuzhev, a researcher at the Donetsk branch of the Committee of Voters.

The party’s support has slumped in recent years, and plummeted even further after Yanukovych’s flight from Ukraine, he adds. But after several rounds of party congresses — including an upcoming nationwide meeting in Kyiv this weekend — members are no doubt looking to regain their footing in a region they’ve long claimed as their home turf.

“The Party of Regions existed before Yanukovych and it will be here after Yanukovych,” says Rovinsky, an aide to Donetsk Mayor Oleksandr Lukyanchenko, a prominent party member.

“The party has a very normal idea: to give more power to the region so that more authority is based here and not in Kyiv.”

Another important factor remains uncertain: the influence of Ukraine’s oligarchs — a handful of businessmen who have traditionally wielded great influence over the government — particularly Rinat Akhmetov, Ukraine’s richest man and a steel tycoon who holds enormous sway over his native Donetsk region.

Observers acknowledge that the Kremlin can always fan the flames of separatism here using its various resources. But that would probably clash with the interests of Akhmetov, whose holding company, System Capital Management, controls a heavy chunk of the region’s industry and has developed close ties with Europe.

“Separatist tendencies generally don’t play into Akhmetov’s interests,” says Ihor Todorov, a professor at Donetsk National University. “In the last 15 years at least, he’s tried to position himself as a civilized, European businessman.”

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But when it comes to influencing the population, that may not help the authorities much, because a large degree of the anger here is aimed at the oligarchs.

They include Petro Poroshenko, a pro-Kyiv chocolate magnate and frontrunner for the presidency ahead of an election set for May, as well as Serhiy Taruta, a metals tycoon the Kyiv government has installed as Donetsk governor.

Reyko, the Russian Bloc activist, says the change of power in Ukraine’s capital has simply “replaced bandits with bandits.”

He points to a recent campaign asking Ukrainians to donate small sums of money via text message to the country’s crippled army.

“Why aren’t these oligarchs helping to fund the army?” Reyko says. “It kills me that people don’t understand that.”