When ex-communist nations such as Poland, Hungary and the Czech Republic joined the European Union 13 years ago, they were shedding the final fetters of a socialist legacy, counting on the grouping’s open borders to bring prosperity and development. Once driven by clunky command economies, Warsaw, Budapest and Prague are bustling, dynamic capitals attracting visitors from around the world — but remain economic laggards compared to their Western European counterparts.

Now, Poland, the region’s largest economy, is leading a dozen countries in Central and Eastern Europe that are trying to eliminate a key hole in their infrastructure that experts believe has held back their economic development. The Three Seas Initiative (TSI) aims to foster closer regional cooperation in building a network of highways, railways and gas terminals — a new connectivity architecture supporters say will better integrate the region with the rest of Europe. Yet some critics wonder whether the initiative could someday rival the EU’s authority in its own neighborhood, and revive Poland’s own historic ambitions to emerge a regional power.

It’s not only a national security, foreign policy or vulnerability issue. David Koranyi, Atlantic Council

Either way, economics is a key motivator. While Central and Eastern Europe account for 22 percent of the EU’s population, according to PricewaterhouseCoopers, they make up only 10 percent of its gross domestic product. With the TSI, its member states — Poland, Croatia, Austria, Bulgaria, the Czech Republic, Hungary, Latvia, Lithuania, Estonia, Romania, Slovakia and Slovenia — hope to reduce their dependence on Cold War–era connectivity infrastructure that runs from east to west by developing a long-neglected north-south corridor. But amid Russian attempts to restore its former dominance in the region, the effort also represents a push by political leaders in countries along the EU’s eastern border to work together to strengthen their security — in addition to economically catching up to other parts of the continent. “It’s not only a national security, foreign policy or vulnerability issue,” says David Koranyi, an energy expert at the Atlantic Council and part of the team that first proposed the idea to European policymakers. “It’s also a competitiveness issue.”

Alliances in the region aren’t new: The Visegrád Group, a four-country bloc of Central European countries, has long aimed to boost cooperation among the Czech Republic, Poland, Hungary and Slovakia in sectors such as energy and defense. But the TSI is far broader in scope, encompassing 11 ex-communist countries plus Austria, and involving infrastructure projects connecting the Baltic, Adriatic and Black Seas. Among these projects is the Via Carpatia highway, which, when completed, would stretch from Klaipeda, Lithuania, to Thessaloniki, Greece, linking key cities along the EU’s entire eastern wall. Another project aims to connect Poland’s new liquefied natural gas (LNG) terminal with Croatia’s own such station. LNG has long been hailed as a key alternative to Europe’s reliance on Russian natural gas, which provides the Kremlin geopolitical influence within Europe. According to Lukasz Janulewicz, a research fellow at the Budapest-based Central European University, the TSI fills major infrastructure gaps — roads, railways, pipelines and more — that couldn’t have been addressed within the Visegrád framework. “It’s also symbolically quite important that these countries are taking the initiative themselves,” he says.

But some question what’s behind that initiative. Critics claim the effort is uncannily similar to an early-20th-century attempt by Poland, the TSI’s leading champion, to establish itself as a regional power. Back then, Polish leader Jozef Pilsudski’s Intermarium strategy envisioned a federation of Central and Eastern European states, anchored by Poland, that would balance out Russian and German power. While it was meant to guarantee continental stability, it was also a clear assertion of Poland’s aspirational role in the region — not necessarily something Brussels is keen to promote today.

“The fact that the main stakeholders are still the same suggests that not much has changed,” says Daniel Bartha, executive director of the Centre for Euro-Atlantic Integration and Democracy in Budapest, adding that the idea has merely been “significantly rebranded” to attract other participants. Polish President Andrzej Duda has assured skeptics the initiative is aimed principally at economic security. But the nationalist rhetoric of Poland’s right-wing government, which is often at odds with Brussels, has stirred concerns about ulterior motives, especially as euroskeptic populists elsewhere in the region gain increasing sway. President Donald Trump’s endorsement of the TSI during a visit to Poland last summer hasn’t helped, though relations between Washington and Warsaw have cooled in recent weeks because of a Polish law that punishes suggestions that the country was in any way responsible for the Holocaust.

Yet supporters dismiss those concerns. Koranyi, the Atlantic Council expert, says the initiative wouldn’t be able to reach its full stated potential without political or financial support from the EU. The real challenge, he says, will be getting national governments and key agencies in each partner country to fully commit to the initiative, and securing private funding to fully develop the projects its architects envision. Attracting American investment aimed at strengthening transatlantic ties is also part of the picture, Koranyi adds.

It’s too early to tell whether the TSI will work and spark broader political cooperation, or falter like so many partnerships have through history. Either way, Eastern Europe’s geopolitical landscape appears set to change. And once again, Poland is taking the lead.

This article has been updated since its original publication on January 15, 2018.