WASHINGTON—On April 28 and 29, Croatia will host the annual Three Seas Summit and Business Forum in Dubrovnik. It’s something of a homecoming. In 2016, the Three Seas Initiative was launched from that coastal city with the goal of accelerating the development of cross-border energy, digital, and transport infrastructure between the Baltic, Black, and Adriatic Seas. A decade after that first meeting, the approaching Dubrovnik gatherings will convene the region’s heads of state and government, officials from the European Union (EU) and partner states, and top business leaders to chart the initiative’s future.

While there is much to celebrate about the initiative’s accomplishments over the past decade, leaders will also need to make important and difficult decisions in Dubrovnik about how it should evolve.

Since the 2016 Dubrovnik summit

The Three Seas Initiative rests on a foundation of significant economic potential, with its thirteen members currently comprising 120 million Europeans (more than a quarter of the EU’s population) and more than $3 trillion in economic power. It was founded by twelve Central European states through the leadership and partnership of the presidents of Croatia and Poland, but has since expanded to include Greece in 2023. The initiative’s member states boast an economic growth rate roughly double that of the rest of Europe. Together, they are addressing an estimated infrastructure shortfall of some 600 billion euros to 1 trillion euros when compared to that of Western Europe.

The institutional cornerstone of the effort is the Three Seas Initiative Investment Fund, launched in 2020, which has raised some $1 billion in contributions from member states and an additional $300 million from the United States International Development Finance Corporation. The fund’s aim is to leverage private capital to catalyze regional infrastructure development. The fund has committed over 800 million euros across nine countries, tangibly contributing to the region’s economic growth. While the fund itself has not captured the $3-5 billion dollars in private capital that was envisioned, regional leaders have said its return on investment approaches 15 percent, which highlights the Three Seas region’s economic potential and validates the initiative’s underlying rationale.

At the 2026 Dubrovnik summit and beyond

The agenda at the upcoming summit aims to be forward-looking. Among the issues that will be discussed by the heads of state and government, four stand out as the ones that will make this summit an especially important one for the initiative’s future.

First, the Croatian hosts are placing an emphasis on the relationship between the Three Seas countries and other international corridors spanning the Eurasian landmass, notably the India-Middle East-Europe Economic Corridor and the Middle Corridor, which stretches through the Caucasus and Central Asia. Both corridors have natural linkages to Three Seas countries and have the potential to facilitate billions of dollars of trade. Reflecting these linkages, Croatia’s government has invited delegations from Gulf Cooperation Council countries and India to the summit. Connecting these regions with the Three Seas can further enhance the economic relevance of the initiative, and it’s also a sound way to attract investment from the Middle East and Indo-Pacific.

The second issue is the need to add a more robust institutional foundation to the Three Seas. When the initiative was first launched in 2016, leaders agreed—and many strongly asserted—that it must be an informal initiative with no permanent structure aside from its membership. As a result, the initiative, aside from the investment fund, has been largely driven by its annual summits and business forums, often going into abeyance for months between these convenings. That’s why the Three Seas Initiative should establish a formal secretariat. A secretariat would offer the means to ensure greater continuity between summits, serve as a repository of existing and potential infrastructure projects, help push for regional policies and legal harmonization to catalyze those projects, and be a 24/7 marketing arm for the initiative and the region. Without such an office, it is hard to imagine how the Three Seas Initiative can reach a higher level of productivity.

The future of the Three Seas Investment Fund is a third critical issue. The fund is in many ways a remarkable achievement. Nine of the thirteen Three Seas states contributed to the fund and established a model of government monies being soundly and profitably invested free of political interference. However, for a number of structural reasons, the fund has been unable to attract the envisioned amount of private capital. As the fund is close to using up its capital, Dubrovnik provides an opportunity to assess the lessons learned and to either adjust the structure of the fund or launch a new one.

The future membership of the initiative is a fourth issue that will be on the minds of Three Seas leaders—and like nearly all Three Seas decisions, this will require full consensus. Following Greece’s accession to what was initially a purely Central and Eastern European initiative, some have suggested Finland as a potential member, highlighting its Baltic coastline and geographic position on Europe’s eastern frontier. While only EU member states have traditionally been considered eligible to join, Three Seas states should nevertheless look to EU candidate countries as prospective future members of the initiative. For example, Western Balkans countries offer greenfield infrastructure opportunities that are geographically encircled by Three Seas states. But Ukraine, currently a Three Seas Initiative associate member, stands as the prospective full member of greatest strategic value and urgency. It is a nation that has succeeded in weathering an existential attack for more than four years, in part because of its proven economic capacities and potential. Integrating Ukraine into the Three Seas Initiative is an opportunity to boost the initiative’s economic strength; it should also, and perhaps even more importantly, be embraced as a moral imperative.      

Since the last Three Seas Summit in Dubrovnik, the initiative has achieved considerable success. It is an established regional forum that has generated increasing global interest. It launched a fund that yielded strong returns and highlighted the region’s profitability. The challenge before the upcoming Dubrovnik convenings will be evolving the Three Seas Initiative into a more powerful and effective driver of regional infrastructure growth. That will require real effort to tie the initiative into global trade routes, achieve greater institutionalization, adopt a more effective approach to private capital, and expand its membership to other democracies between the Baltic, Black, and Adriatic Seas.