BRUSSELS, Belgium — The countries of Central and Eastern Europe have been getting a lot of bad press lately.

The Czech Republic is embroiled in a sex-and-bribery scandal after anti-corruption police swooped in on the prime minister's office and arrested his glamorous head of staff.

Bulgaria's government has been in power only three weeks, but already faces mass demonstrations demanding its resignation over graft allegations.

The European Parliament has accused Hungary of lurching toward authoritarianism.

And Slovenia is struggling to avoid becoming the next euro zone bailout case.

The turmoil comes almost a decade after most countries of the former Soviet Bloc joined the European Union, decisions that were hailed at the time for promising to cement their transformation into stable western democracies.

As the EU prepares to add Croatia as its 28th member July 1, however, some are now raising questions about the real impact of the union’s eastward expansion.

"There is a terrible fragility and weakness in parts of this enlargement, we are seeing this in Hungary now," says Judy Dempsey, senior associate at Carnegie Europe.

She calls Romania and Bulgaria’s 2007 entry into the EU "a disaster."

"The institutions of democracy, the practice of democracy, the implementation of democracy are not taking root,” she adds. “We need much, much stronger pressure on these countries to pursue reforms."

That concern runs to the top of the EU. European Energy Commission Gunther Oettinger, the most senior German official at the EU's head office, described Romania and Bulgaria last month as "ungovernable."

European lawmakers are urging the bloc to consider the unprecedented step of suspending Hungary's voting rights in the EU unless Prime Minister Viktor Orban backs down over plans to revise the country's constitution and legal code they say would undermine judicial independence, media freedom and human rights.

However, the recent slew of bad headlines belies what others see as far more positive underlying developments across much of Central Europe since eight former communist countries joined in 2004, followed by Romania and Bulgaria three years later.

Despite their current problems, most of those countries are firmly rooted in mainstream European democracy after having made remarkable progress.

Poland has emerged as a major player in European affairs. With its average GDP growth of more than 4 percent a year since joining the EU, it’s the only member country to have avoided slipping into recession at any time since the global financial crisis of 2008.

The fact that the Brussels rumor mill has several of Poland's leading politicians in pole position for top jobs at the EU and NATO that will be up for grabs next year illustrates the respect they’ve earned across the continent.

In Eastern Europe, the former Soviet Baltic republics have emerged from deep recession in 2008 to occupy the top three positions in the EU's economic growth rankings.

Estonia in particular has emerged as a model for small, open economies by successfully developing its high-tech sector. Latvia's sound economic management has won it the green light to join the euro zone in January, the fourth former communist state to join following Slovakia, Slovenia and Estonia.

"The European integration process has acted as a catalyst for sweeping reforms in democratic, economic and social terms in these countries where otherwise it would not have happened or would have happened a lot slower," says Corina Stratulat, policy analyst at the European Policy Center, a Brussels think tank.

"They haven't just become members of a union of countries, but part of a community of values, democratic political values and principles."

Even those eastern countries with serious political and economic problems have performed well since joining the EU.

In 2001, the average Romanian's purchasing power was only 28 percent of the EU average. By 2011, it had risen to 49 percent. In Bulgaria, the same indicator of personal wealth rose from 30 percent to 46 percent of the EU average, in Hungary from 58 percent to 66 percent, and in Slovenia from 80 percent to 84 percent.

Despite criticism from some quarters that Orban's power grab and the rampant corruption in Romania and Bulgaria have undermined the EU's values from within, officials at the bloc's headquarters are adamant the decision to open the door was the right one.

"It has been proved that enlargement is one of the most successful EU polices," says Peter Stano, the European Commission's spokesman on enlargement issues.

"We are extending the zone of stability and of prosperity, even if that sounds a little ironic in the current circumstances," Stano said in an interview. "If you look at the benefit and results of enlargement you see it’s not a cause of the current problems, it is part of the solution."

The EU's eastward expansion has also brought benefits for the West.

Spanish exports to Poland, which doubled in the past decade, have surpassed those to China. The opening of eastern European markets is estimated to have added 0.4 percent to Austria's yearly economic growth as trade with its neighbors tripled.

Germany sold goods worth $96 billion to Poland and the Czech Republic last year, a combined total that's higher than its exports to China or the United States.

One problem European officials recognize is that while the EU has powerful leverage over aspirant counties — by insisting they embrace democratic standards, tackle corruption and push through economic reforms in order to meet the EU's membership conditions — Brussels has less power to insist nations stick to those commitments once they become members.

That weakness has been thrown into sharp relief by the dilemma over how to respond to developments in Orban’s Hungary.

"Once you're in and things go wrong like in Hungary — and things are going terribly, terribly wrong in Hungary now — the EU actually has very few powers to influence or reverse the bad," Dempsey says from her base in Berlin.

"The real weakness of enlargement is how to follow up on the political reforms, consolidate democracy and strengthen accountability."

Orban's conservative Fidesz party was swept to power with a two-thirds majority in 2010 elections. That gave him power to rewrite the constitution to consolidate the government's power, which prompted widespread international condemnation.

The European Parliament's Civil Liberties Committee on Wednesday warned that Orban's actions risked violating the EU treaty, which enshrines "respect for human dignity, freedom, democracy, equality, the rule of law and respect for human rights, including the rights of persons belonging to minorities."

The treaty enables EU countries to vote to suspend a member’s right to vote in the bloc's policy setting meetings. However, they’ve been reluctant to use that "nuclear option."

When it was threatened in the past, after Austria's far-right Freedom Party was voted into power in 2000, the policy was judged to be a failure that strengthened support for the right-wingers.

EU officials are painfully aware that a heavy handed response to Hungary could bolster the ultranationalist Jobbik Party, whose views on Jews, Gypsies and other minorities — combined with expansionist designs on neighboring nations — make it even more distasteful than Orban.

The EU says it’s learned its lesson from such problems. Application tests of democratic and rule-of-law principles were tightened for Croatia and other potential members.ju

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They include Iceland, which was expected to be next in line after the Croats until its citizens developed cold feet and put membership negotiations on hold.

Albania, Macedonia, Montenegro, Serbia, Kosovo and Bosnia are all keen to sign up, but are a long way from meeting membership conditions. Turkey is also a candidate, but its negotiations have stalled with little enthusiasm from either side to revive them.

That means the party planned in Zagreb July 1 may be the last to celebrate the EU's expansion for some time.