Looking to a decade of delivery: The Three Seas Initiative charts its course forward
Bottom lines up front
- The Three Seas Initiative hosted its 10th anniversary summit and business forum in Dubrovnik to highlight the need for Central European connectivity..
- Participants discussed the importance of resilient energy supply chains, keeping pace with digital innovation, a long-term solution to mobilizing capital, and connecting to broader geo-economic networks.
- To drive the initiative forward, it should take steps to stand up a permanent secretariat, prioritize private capital and EU funding opportunities, and expand the initiative to Ukraine, Moldova, and the Western Balkans.
Introduction
On April 28–29, 2026, the Three Seas Initiative convened in Dubrovnik, Croatia, to celebrate its first decade and chart its way through the next. The initiative, launched in the same city in 2016, aims to accelerate the development of cross-border energy, transport, and digital infrastructure across the region between the Baltic, Black, and Adriatic Seas. The convening consisted of a formal governmental summit and a business forum that attracted international engagement from more than 1,200 participants from forty-five countries; active involvement by partners including the United States, European Commission, Japan, Spain, and Turkey; the announcement of Italy as a new partner country; and the launch of a new Three Seas Fund of Funds led by the European Investment Bank. Reaching such a global audience, the events underscored the Three Seas Initiative as an established brand and the growing international interest in the region’s economic potential.
Former Croatian President Kolinda Grabar-Kitarović, co-founder of the initiative, captured the theme and outlook of the summit and business forum when she called on the initiative and its leadership to yield a “decade of delivery” of tangible results. This report will explore the key outcomes of the Dubrovnik convenings as well as the next steps needed to realize the initiative’s goals and its vision of a Europe whole, free, undivided, and secure.
Background
The Three Seas was launched in 2016 by the then presidents of Croatia and Poland as an innovative project aiming to address a more than $1-trillion infrastructure gap in the region between the Baltic, Black, and Adriatic Seas when compared to Western Europe. The initiative began with twelve European Union (EU) member states in Central and Eastern Europe determined to overcome decades of underinvestment during the Soviet Union’s domination. That legacy left the region economically weakened, militarily underprepared, dependent on Russian energy, and bereft of cross-border regional connectivity, particularly running from the region’s north to its south. Built on the belief that infrastructural connectivity is necessary to fuel regional prosperity, security, and resilience, the Three Seas Initiative aims to bolster investment in cross-border energy, digital, and transport infrastructure within the region.
The initiative seeks to leverage the region’s sturdy economic foundation—notably including a highly skilled population of 120 million, growth rates more than double those of the EU as a whole, and rates of return on investment approaching 8.8 percent—to attract private capital. Central to this effort is the Three Seas Initiative Investment Fund (3SIIF), which was launched in 2020 to combine the power of private capital with funds from regional countries and partners. Since its launch, the fund has achieved returns as high as 12–15 percent while investing in five projects under the initiative’s mandate.
In addition to the establishment of the 3SIIF, the initiative has successfully generated interest within Europe and the broader international community. Beyond its initial twelve members, the Three Seas expanded to include Greece as a full member in 2023. Ukraine and Moldova joined as associate members that same year, with Albania and Montenegro following their path in 2025. Further abroad, the initiative curated a robust international network featuring partners such as the United States, Japan, the European Commission, Germany, Spain, and Turkey. The initiative’s annual summits have underpinned its deepening engagement with these partners and associate members, providing a forum to consider opportunities to strengthen this pivotal region. At US President Donald Trump’s suggestion at the 2017 summit in Warsaw, the region has hosted business forums alongside the summits to highlight the region’s opportunities directly to the private sector and foster the public-private collaboration needed to accelerate infrastructure development.
Outcomes of the 2026 Dubrovnik Summit and Business Forum
The two days in Dubrovnik featured discussion regarding five key topics: connection to global economic corridors, energy infrastructure, digital infrastructure, transport infrastructure, and financing.
Three Seas and global economic corridors
The Three Seas Initiative’s goals extend beyond connectivity among its member states to enhancing the region’s connectivity to the broader global economy. With this in mind, the Croatians, as the hosts of the Dubrovnik convenings, made connecting the Three Seas and other regional and global economic and trade corridors a defining theme. Three specific corridors were featured: the India–Middle East–Europe Economic Corridor (IMEC), the Middle Corridor, and the Adriatic–Ionian Corridor. This focus was unique to the Dubrovnik events, with no previous summits placing such emphasis on the importance of leveraging other geoeconomic corridors.
IMEC is an initiative focused on energy, digital, and transport infrastructure along a corridor stretching from India, through the Arabian Peninsula, and terminating in Southern Europe. Because of the IMEC’s natural ability to connect the Three Seas region to Asia, enhancing its economic opportunities and creating new trade routes, it was a top discussion point ahead of and during the events in Dubrovnik. With current plans for an IMEC route to end in Greece—a Three Seas member—the initiative presents an opportunity to connect ports into and land routes across Central and Eastern Europe. This linkage’s potential should attract interest and investment, particularly from IMEC countries in the Midde East seeking to leverage the opportunities and markets offered by the Three Seas region. However, patience and creative solutions will be needed to work around ongoing instability in the Middle East, which closed key routes and deterred investors at the time of the Dubrovnik convenings.
The Three Seas Initiative was originally founded with a geopolitical lens, aiming to reduce dependence on Russia and bolster security along Europe’s eastern flank, which has become increasingly important following Russia’s 2022 invasion of Ukraine. Similarly, the Middle Corridor provides the best option for a land route between Europe and China that bypasses Russia by running through Kazakhstan, the Caucasus, and Turkey into Romania, Ukraine, and Poland. Linking these two projects enables both regions to synchronize their efforts, creating greater flexibility and interoperability. Three Seas received a vote of confidence from Turkey’s foreign minister, who described it as an “integral part of the Middle Corridor,” which bodes well for the two corridor’s future connections.1Unless linked or noted otherwise, quotes are taken directly from the proceedings of the summit or business forum being discussed.
The third and final economic corridor highlighted throughout the Croatian Three Seas presidency is the Adriatic Ionian Corridor, a network of regional integration initiatives navigating from Italy to Greece through the Western Balkans. The corridor overlaps significantly with the Trans-European Transport Network (TEN-T) and its goals align neatly with the Three Seas, especially in the transport realm, providing a clear and tangible path toward integrating the Western Balkans into existing and developing European infrastructure. Given Croatia’s close ties with the Western Balkans and history of advocating for the region’s EU and transatlantic trajectory, its Three Seas presidency highlighted the importance of connecting this region to Central Europe to overcome long-standing inefficiencies and underinvestment resulting from complicated geography, uneven integration, and complicated history.
Energy infrastructure
Of the three pillars, energy received the most attention throughout both the summit and business forum—an unsurprising development given the region’s significant efforts to reduce its dependence on Russian oil and gas, and the further urgency created by the disruption of energy supplies from the Middle East in light of the 2026 US–Iran conflict. Further driving excitement around energy was the participation of US Secretary of Energy Christopher Wright, who emphasized the Three Seas region’s potential by saying that it “is where the prosperous, long-term, energized, and moving forward future of Europe is going to come from.” The initiative’s next stage has been undergirded by a focus on investment in nuclear and renewables as a long-term priority to improve energy security, along with continued emphasis on diversifying and expanding liquified natural gas (LNG) imports in the interim.
Toward this end, the Vertical Corridor has emerged as a cornerstone project within the Three Seas region. Transiting Greece, Bulgaria, Romania, Hungary, and Slovakia among active members, as well as Ukraine and Moldova among partners, the Vertical Corridor creates a north-south route to transport LNG by connecting and occasionally upgrading existing infrastructure. In light of rapidly changing gas prices after Russia launched its 2022 invasion of Ukraine, and compounded by uncertainty in the Persian Gulf, Maria Sferruzza of Greece’s National Natural Gas System Operator (DESFA) argued that the Vertical Corridor is “an opportunity to mitigate volatility.” Further emphasizing the role of global crises, prices and availability were deemed “not supply and demand anymore, [but] energy geopolitics” by political scientist Francesco Sassi, highlighting the case for greater Ukrainian integration into strategic energy efforts.
The summit also highlighted nuclear power as a critical element in the region’s energy mix for the long term and necessary to strengthen and sustain its economic health and security. Underscoring Poland’s national commitment to, and regional interest in, increasing the role of nuclear power, Polish Energy Minister Miłosz Motyka described nuclear as a “foundation block of new security.” With Three Seas countries prioritizing reducing electricity costs, the region has been forward leaning in its plans to leverage nuclear power, and the political will needed to drive investment in this area remains strong. However, private-sector leaders stressed the need to streamline design processes, standardize supply chains, and provide regulatory certainty and consistency to ensure that nuclear emerges as a sustainable, cost-effective option for Central Europe.
The Dubrovnik discussions reflected how the Three Seas region has shifted from a period of defensive, reactive (but necessary) energy diversification toward a strategy for institutionalized regional energy architecture. Energy security remains a paramount driver, but greater emphasis was given to the requirements of execution—including the scaling of finance through public-private partnerships, increasing cross-border regulatory harmonization, and the development of more robust capital markets.
Digital infrastructure
The Three Seas tech sector is increasingly competitive globally with firms producing cutting-edge software, satellites, drones, and data centers, among other capabilities. The Dubrovnik convenings highlighted several digital projects in the Three Seas region that underscore its digital growth and potentials.
- Project Pantheon: A transatlantic investment group is funding a next-generation data center in Croatia, a $50-billion project that promises to reinforce the region’s digital infrastructure and artificial intelligence (AI)-driven growth.
- Regional satellite data sharing system: On the side of the Dubrovnik meetings, companies from Croatia, the Czech Republic, Greece, Poland, Slovakia, and Slovenia signed a letter of intent to provide Earth observation capabilities through shared satellite resources and integrated ground infrastructure.
- GreenMed fiber-optic cable: This next-generation express digital corridor will run from Italy across the Adriatic Sea through Croatia, Montenegro, Albania, Greece, and Turkey, and into the Middle East.
- Intelligence resilience nodes: Damir Habijan, Croatia’s minister of justice, administration, and digital transformation, is driving forward his nation’s proposal for a regional network of secure data centers to provide redundant storage for the data of Three Seas governments and their civil constituents.
However, much more must be done if the region is to truly unleash its digital potential and avoid being left behind in the AI revolution. More data centers are needed to match the rapid growth of data management demand. Increased data connectivity across the region is needed to leverage the combined power of national data networks, in turn requiring careful planning and significant growth in the energy sector to match the demands of a vibrant Three Seas digital network.
Achieving scale is the central requirement for a robust, globally competitive regional digital economy, as emphasized by Jacek Kosiec, chief executive officer of Poland’s Creotec Geo, among others. The key to success in this regard is developing a robust combination of capability and connectivity. How 3SI addresses these challenges will determine whether the region can be a global contributor to the evolution of AI or simply a consumer.
Transport infrastructure
Dubrovnik, “a city built on trade, diplomacy, and logistics” according to Maersk Line’s Camilla Jain Holste, served as a fitting location to address the Three Seas region’s transportation challenges and opportunities. The region features more than twenty significant ports including Gdansk, Constanta, Rijeka, Koper, and Thessaloniki. However, the potential of these logistic hubs has yet to be fully realized due to the need for modernization and expansion, as well as inadequate and undeveloped intra-regional road and rail. Leaders at the business forum and summit emphasized the need to accelerate the development of the region’s ports, road and rail networks, and intermodal facilities, and the need to secure that infrastructure.
Croatia’s port of Rijeka and Romania’s Port of Constanta were highlighted as national strategic projects and Three Seas success stories. Roughly €380 million and €1.1 billion, respectively, have been invested to modernize and expand their facilities. These projects reflect the region’s determination to modernize its ports, making them more efficient and cost-effective, including through digitalization of operations, the development of modern multi-modal capacities, and improved linkages to road and rail networks.
According to the Centre for Eastern Studies’ Sandra Barniak-Stakowiak, high-speed rail is a “game changer that could redefine connectivity and integration across the region.” However, rail speeds within the Three Seas region lag significantly behind those in Western Europe, with 60 percent of Eastern European rail networks having speeds below 60 kilometers per hour (km/h) compared to 20 percent in Western Europe. While projects are in progress in Poland, the Czech Republic, Hungary, and the Baltics, high-speed rail across the region has been impeded by a lack of sustainable financing, and cross-border legs are hampered by a lack of regional governance and standards. The complexity of high-speed rail was noted throughout the Dubrovnik events, especially given differing technical and engineering requirements. For example, Jose Maria Ilorente Galean of Spain’s Ineco noted that trains operating across borders often require four or five different signaling systems. Beyond calls for a more robust European vision for rail networks and the harmonization of standards, Nippon Koei Company’s Masahiro Nakamura highlighted Japan’s integration of private and public capital as a possible model for the Three Seas to deepen the financial foundation for railroad expansion and modernization.
The role of roads, rail, and ports in regional security and the security of these infrastructure networks emerged as a prominent theme in Dubrovnik. Panelists underscored the need to invest in infrastructure that can bear the weights and sizes of military equipment and often dangerous—that is, explosive—military cargo. This requires close engagement with defense officials at the earliest phase of planning national and cross-border transportation routes. Moreover, threats to infrastructure are growing and are “a new reality of today,” emphasized Ian Lesser of the German Marshall Fund. Having a diversity of routes and ports strengthens security and resilience, but they must be protected from sabotage, direct attacks, and cyberattacks—a conclusion underscored by Russia’s invasion of Ukraine and subsequent incidents in the Three Seas region.
Financing
While the Three Seas Initiative traditionally has three functional pillars, leaders referred to finance as the “fourth piece of the puzzle” and recognized the ongoing momentum of existing financial tools—such as the 3SIIF and Innovation Fund—throughout the course of the Dubrovnik Summit and Business Forum. A pivotal outcome was the European Investment Bank (EIB) and five regional countries (Poland, Romania, Lithuania, Slovenia, and Croatia) signing a memorandum of understanding (MOU) to launch the Three Seas Initiative Infrastructure Fund of Funds with a goal of unlocking €2 billion in funding for infrastructure projects. The expectation is that participating countries will provide €250 million in funding, matched by the European Investment Fund, and raise private capital to meet this ambitious goal while addressing limitations uncovered by the 3SIIF. While the region will eventually need significantly more than €2 billion to fully overcome the historical investment deficit, developing investor confidence in the region with support from the EIB is key to longer-term gains.
EU financing was also a prominent theme due to ongoing negotiations for the next Multiannual Financial Framework (MFF), which will fund the EU from 2028 to 2034. Given the overlap between transport, digital, and energy infrastructure, with infrastructure benefiting European security or energy security, officials and business leaders advocated for leveraging funding from the MFF to support Three Seas projects.
In addition to addressing the issue of raising necessary funding, discussions homed in on the importance of integrating capital markets, clarifying regulatory frameworks, and leveraging new financial instruments to enable greater financial scale and efficiency. Despite progress made toward securing funding, the absence of mature capital markets continues to hinder greater progress within the financing sphere. As EU countries have historically depended on funding from banks, smaller economies are at a significant disadvantage in terms of generating and accessing capital, especially in terms of long-term financing for infrastructure. Throughout discussions, experts argued for greater capital market integration across the EU as a key step to enable the mobilization of private capital at the scale necessary to rapidly develop infrastructure in the Three Seas region.
A more global outlook for Three Seas
Over the course of two days in Dubrovnik, forty-five countries were represented at the business forum, demonstrating its potential to solidify an international network of partners and investors.
Within Europe, the biggest news was Three Seas welcoming Italy as a new partner. Discussions around Italy’s interest previously focused on connecting the Adriatic port city of Trieste, especially given plans for Trieste to serve as one of the entry points for IMEC in Europe. The decision to deepen its engagement with Italy represents a new strategic direction for the Three Seas Initiative, focusing on leveraging Central Europe’s potential as a key connector in a broader, more international infrastructure puzzle—an evolution from primarily selling the region’s economic opportunities within Europe and the transatlantic community. Considering its central role in the Middle Corridor, Turkey’s involvement further solidifies this point.
No changes were made to the core membership of the Three Seas in 2026, but the summit saw enthusiastic participation from associate members, including the prime ministers of Ukraine and Moldova and presidents of Albania and Montenegro. Their continued engagement is a positive signal for the initiative’s growing relevance and provides an opportunity to reinforce the message that excluding non-EU member countries risks leaving a dangerous hole in Europe’s eastern flank—repeating the situation that created such a dramatic investment gap in the Three Seas region in the first place.
A continued forum for transatlantic engagement
Since its inception, the Three Seas has sought to tie itself to the transatlantic community, and a strong US presence demonstrates dedication on both sides of the Atlantic to ensuring its success. Having traditionally received bipartisan support among US officials, especially given its nature as a commercially driven project, the initiative is an important forum for engaging with the United States. Beyond the importance of unlocking US financing, whether public or private, a US presence demonstrates a commitment to this specific regional element of the transatlantic relationship and supports Central European countries’ efforts to establish themselves as leaders within the transatlantic community.
In Dubrovnik, the US delegation was headed by US Secretary of Energy Wright alongside high-level representation from the Department of State and the International Development Finance Corporation (DFC). As such, the US commitment to the Three Seas region was perhaps most prominent in the energy sector, with Wright stating, “The US is unleashing a new era of cooperation for Central and Eastern Europe. These partnerships are rooted in our mutual support of an energy addition agenda—more jobs, more opportunity, and more investment.” Toward that end, Wright and regional leaders signed an MOU launching a “Trump Peace Pipelines Framework” that will leverage the Vertical Corridor. They also issued a joint statement supporting the expansion of the Southern Interconnection Gas Pipeline to facilitate the import of US natural gas, a joint statement with Croatia to advance the nation’s ability to leverage small modular nuclear reactors (SMRs), and a Croatian SMR feasibility study.
Toward a decade of delivery
With leaders from nine member states together on stage alongside founding Presidents Duda and Grabar-Kitarović during the business forum, a consensus emerged that the Three Seas Initiative had succeeded in redefining the narrative around Central and Eastern Europe, emphasizing its potential and opportunities. Czech President Petr Pavel concluded that, after decades of the region “developing within our national borders, missing interconnection,” the Three Seas provided the space for countries to build the people-to-people links needed for greater resilience. Toward this end, President Duda said the Three Seas creates a space for its members to “develop our countries as an important part of the European community.” However, to achieve this vision of a fully integrated Central Europe, Grabar-Kitarović maintained that the initiative must ensure its objectives are “deliverable, bankable, realistic, and implementable.”
Based on the discussions in Dubrovnik and key recent accomplishments, the recommendations below should be key elements of a strategy to increase the momentum and tangible impact of the Three Seas Initiative.
Build an institutional home: When the Three Seas was launched in 2016, a conscious decision was made to operate it as an informal coalition free of cumbersome bureaucracy. In the early years, there was value to this approach, as it allowed member states time to establish confidence in the initiative’s structure and focus and to consolidate priorities. The downside is that it has limited the initiative to a stop-and-go undertaking driven by its annual summit and business forum. As these events approached, a rush of activity would occur to ensure sound deliverables but, after the summit, any momentum achieved would languish for months until the next convening approached.
To truly unlock the potential of the initiative, a permanent front office with a modest staff should be established. It should be tasked with marketing the region’s opportunities; serving as a repository of infrastructure projects, opportunities, and points of contact; convening the annual summit and business forum, as well as other events to advance the cause; and generating regional initiatives that would make cross-border infrastructure projects in the region easier to execute and more attractive to investors. To develop greater cooperation with European structures, improve access to private capital, and root the Three Seas as a fundamentally European organization, the institution should be based in Brussels, an appropriate location close to many multinational institutions and large financial centers.
Step up efforts to attract private capital: The Three Seas Initiative was launched as a commercially driven initiative, building on attractive regional potentials to create impressive returns for investors. While the 3SIIF successfully demonstrated the proof of concept for a regional fund by proving its profitability, it did not achieve its goals in terms of attracting private capital. The lessons learned from the otherwise successful 3SIIF must be incorporated into the EIB Fund of Funds, and the Three Seas must now reinforce its efforts to mobilize private financing. The aforementioned secretariat is a strong step toward this end, but further integration of capital markets and regulatory reform will also be key.
Additionally, discussions in Dubrovnik highlighted how investment opportunities frequently find investors rather than the other way around, with speakers noting the importance of governments playing an active role in promoting projects. With this in mind, the initiative and its member states should go on the offensive, with a plan to seek out funding rather than passively expecting it to find the Three Seas. Despite the economic successes of the region, general knowledge about its economic opportunities have not yet fully permeated the global financial community.
Leverage EU funding opportunities: As the next MFF is being negotiated, Three Seas members should pursue areas of natural overlap with EU programs. Though still under discussion, the current target for the MFF will significantly increase the EU’s overall budget, from an expected roughly €1.1 trillion from 2021–2027 to a targeted €2 trillion for 2028–2034. This presents an opportunity for the Three Seas to leverage new programs and funding, especially as new synergies have emerged between the priorities of the initiative and the EU. For example, the MFF emphasizes the energy transition, aligning with the initiative’s historical focus on energy security. Moreover, the creation of the dedicated European Competitiveness Fund that will prioritize innovation, digitalization, technology, and security further complements the initiative’s goals, especially in the digital and energy pillars.
With this in mind, the Three Seas must realize the opportunity at hand and work alongside partners in Brussels to unlock greater funding for its projects. While EU funding alone cannot push the Three Seas into a new era of delivery, it can certainly help develop robust projects serving broader European goals while demonstrating the value of infrastructure in the region to external investors.
Expand membership to partner countries: As the Three Seas increasingly develops a geopolitical voice in Europe, it should reconsider its stance on membership for EU candidate countries to bolster its impact and avoid creating a new connectivity problem. Were partners such as Ukraine, Moldova, and the Western Balkans to be fully integrated into the initiative, the Three Seas would concretely change Europe’s geoeconomic landscape by removing a long-standing barrier to broader regional prosperity in uneven infrastructure development. Without these partners, the Three Seas propagates the situation it finds itself in by creating a new infrastructure gap, this time within Central and Eastern Europe.
The primary focus of the Three Seas should not be just the infrastructural integration of its member states, but also the completion of an undivided Europe. The Three Seas should lead by example when it comes to Europe’s integration of Ukraine, Moldova and the entirety of the Western Balkans. There is urgency in this undertaking as Ukraine and Moldova grapple with Russia’s invasion and interference and as both China and Russia continue to target the Balkans as the weak underbelly of Europe. To guarantee its long-term success, the Three Seas Initiative must keep the vision of a Europe whole, free, prosperous, and at peace at the heart of its mission.
Acknowledgments
The Atlantic Council received funding from the government of Croatia to support Three Seas Initiative work surrounding the 2026 Dubrovnik Summit and Business Forum. This report was produced with strict commitment to our intellectual independence policy.
About the authors
Emma Nix is an assistant director at the Atlantic Council’s Europe Center where she serves as the staff lead for Central Europe and the Three Seas Initiative, and supports the Center’s work on the European Union.
Ian Brzezinski is a senior fellow at the Atlantic Council and directs the Europe Center’s work on the Three Seas Initiative. He is a former deputy assistant secretary of defense for Europe and NATO policy.
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Image: Member state leaders meet for the annual Three Seas Summit on April 28