Over the last six decades, no part of European integration has been as transformational as the gradual enlargement of what is now the European Union. The EU’s expansion brought democracy to places that knew only authoritarian rule. It turned what was a perennially conflict-ridden continent into one of the most prosperous regions in the world.

From the beginning, the number-one aim of integration was to reconcile France and Germany, which had fought three wars within less than a century. To do so, the two countries tied together their steel and coal industries in July 1952—the symbols and substance of power in those days. In the following years, multiple European states continued to merge their economies in various ways, forming the institutions that eventually turned into the EU. Each wave of enlargement had a different aim. After the dictatorships of Greece, Portugal, and Spain fell in the mid-1970s, these countries joined the entity in a successful effort to stabilize their fragile democracies. After the Soviet Union collapsed in 1991, the bloc naturally admitted Europe’s previously neutral nations, Austria, Finland, and Sweden. Over the following decade, it welcomed the ex–Warsaw Pact countries of Europe and the Baltic states, as well as parts of the Balkans.

During each round, many analysts feared that expanding the bloc would dilute it. But these concerns never came to pass. Instead, growth has gone hand in hand with deepening ties and connections. Originally, for example, all the bloc’s decisions had to be unanimous, which inhibited collective action. But when the EU introduced the integrated single market in 1993, it began making most of its decisions by a supermajority in most of the different councils of ministers (although still many decisions in practice are taken by consensual.) There is of course, a co-decision mechanism with the European Parliament on all legislative issues. There are also important domains where decisions must still be unanimous, notably on foreign affairs, and there are wide areas in which policymaking still lies primarily with different member states. But the EU today has far more power within its members than ever before.

There have, however, been setbacks in the process of enlargement. The United Kingdom played an important role in the bloc’s integration for half a century until, in a burst of populism, it decided to leave in 2016 (although a large majority of British people regret that decision). Turkey started negotiations on accession in 2005, but setbacks in its democratic development and continuing disputes over Cyprus have continuously delayed its application.

The biggest setback involves the countries in the western Balkans. At a summit in Greece in 2003, every Balkan state was promised membership, but since then, only Croatia has managed to enter, joining in 2013. The other Balkan countries have been stalled by bilateral disputes and an unwillingness to reform. Today, the process of EU enlargement in the region has lost both momentum and credibility. EU leaders continue to pay lip service to the idea of admitting the western Balkan countries, and they continue to issue reports and hold meetings about their accession. But nothing of meaning has really been done. In fact, in 2019, when it seemed possible that Albania and North Macedonia were ready to join (after Greece had spent over a decade blocking Albania’s acceptance), France, Denmark, and the Netherlands suddenly issued vetoes, stopping the process.

But now, Russia’s aggression against Ukraine has changed everything. Suddenly, the peace and stability of all eastern Europe is under assault, with vast consequences for the continent as a whole. The result has been a quantum shift in numerous EU policies. The organization has entered a new phase in its development in which it is tasked with bringing stability to its flank—a goal that is bound to dominate its attention for years to come. And to meet these challenges, the EU is poised to embark on a new wave of enlargement with major consequences for the future of the continent. It will start by entering accession negotiations with Moldova and Ukraine, and other states will follow.

To increase the size of the EU again, possibly to more than 30 states in the 2030s, will not be easy. This expansion will provoke intense haggling over institutional reforms, fierce fights over budget and financing, and endless maneuvering to ensure some sort of balance between the acceptance of Moldova and Ukraine and western Balkan countries. How these disputes play out will, to a large extent, depend on how the war in Ukraine proceeds. But the overall aim must be finding a pathway for Kyiv’s accession. Doing so will help bring about prosperity and stability in both Ukraine and all of Europe.

SET IN MOTION

Ukraine has been knocking on the door of the EU for nearly two decades, beginning with the country’s 2004 Orange Revolution, when Ukrainians took to the streets of Kyiv waving EU flags. But within the bloc, support for the country’s candidacy has long been very thin. The EU’s most powerful members were all opposed, citing everything from corruption to fear of alienating Moscow.

Still, Kyiv has inched closer to the body over the last 15 years. After Russia invaded Georgia in 2008, Ukraine, joined by Georgia and Moldova, negotiated deep and comprehensive free trade agreements with the EU. When Ukrainian President Viktor Yanukovych backed away from signing the deal in 2013 under pressure from Moscow, protesters took to the streets, and eventually, Yanukovych fled the country and sought protection in Russia. Russian President Vladimir Putin responded to this setback with violence. Almost immediately after Yanukovych fled, Putin invaded and annexed Crimea and then sent Russian forces into eastern and southern Ukraine to instigate a rebellion. Moscow found little popular support, and at first, Putin ended up controlling just a sliver of Ukraine’s two easternmost provinces. Then, in February 2022, fearing that Ukraine’s democratic and European path would stimulate democratic change elsewhere (and thus threaten his own power), Putin launched his full-scale invasion.

But the invasion backfired, initiating a profound transformation that helped unify and empower Europe. It may now help expand it, too. In June 2022, the heads of EU states decided to grant Ukraine candidate status. This decision was a major policy shift, hitherto unthinkable, but Putin’s invasion made advancing Ukraine’s application a strategic imperative. The future stability of the country is now rightly seen as key to the future stability of Europe. And although there will certainly also have to be extensive security arrangements—probably through NATO membership—to safeguard Ukraine, Europe’s leaders understand that the country’s political and economic integration into the EU is essential to stabilizing Europe, just as previous waves of enlargement helped make the continent peaceful.

The ball is rolling. In late October, the European Commission is expected to release its regular enlargement report. Everything suggests that in December, the EU heads of state and Brussels will green-light formal accession negotiations with Moldova and Ukraine. Actually attaining membership, however, is a complicated process. It requires adopting all the rules and regulations that the EU has decided upon so far, and it means accepting everything in the 36 chapters of the treaties that make up the organization. Negotiations are, in reality, a long process of negotiated surrender by the applicant state, and they always take at least a couple of years. On average, applicant countries need approximately five years to complete negotiations. The quickest joiners, Finland and Sweden, did it in a little over two years, and the slowest, Portugal and Spain, required nearly eight. The process of joining the EU requires more steps today than it did when the last new member, Croatia, entered, so the process now takes longer.

But both Moldova and Ukraine have already fulfilled part of the requirements while implementing their comprehensive free trade agreements. If they can solidify their democracies and sustain their pace of economic, administrative, and judicial reforms, it should be possible for them to conclude their accession negotiations before the 2029 European Parliament elections. Conducting these talks will be one of the most important tasks for the next European Commission, which will assume power after the June 2024 EU elections. This commission must therefore have the strength and the composition to make successful negotiations possible.

MAKING ROOM

There are important obstacles to Moldova and Ukraine’s accession. One is that, throughout the process, there will be pressure to ensure that the countries of the western Balkans are not again left out in the cold. These countries and their supporters want a realistic path to membership—one that runs in parallel with the path for Moldova and Ukraine. This pressure will be justified. The EU still has to ensure that the western Balkans remain stable for the bloc’s own sake, and the western Balkans have been in the waiting room for too long.

That said, it is difficult to envision any shortcuts to western Balkan membership. Ideally, lingering bilateral disputes between Balkan countries will be set aside, but the process of aligning these countries with EU rules, standards, and policies cannot be compromised. To attain membership, Serbia will have to recognize the independence of Kosovo, and Kosovo must adhere to what has been internationally agreed upon when it comes to Serbian minority rights. Bosnia will need to come out of its dependence on international supervision and show that it can really be a sovereign state. Today, international oversight mechanisms can still override its different decisions. But the sight of Moldova and Ukraine moving forward may be the only realistic way of breaking through the various obstacles that have long blocked progress in the western Balkans.

Other EU aspirants face steeper obstacles. Although it was originally part of the vanguard trio of countries seeking to join, with Moldova and Ukraine, Georgia has slipped to the end of the EU queue under its oligarchic rule. In at least the short term, it is unlikely to catch up. Turkey continues to express a desire for EU membership, but it is too far behind on human rights to join today.

Concerns about Georgia and Turkey, however, are unlikely to slow down Moldova and Ukraine’s admission. But Moldova’s and Ukraine’s candidacy will still face obstacles related to whether a new expansion requires overhauling the institutional structure of the bloc. There are already calls for moving away from demanding unanimity for the passage of certain types of measures, and if two more countries join, there will be calls for streamlining the decision-making processes in other respects as well. Still, these are permanent debates within the EU, and an enlargement from today’s 27 members to 29 should not prove too disruptive for the body’s structure. After all, until Brexit, the EU had 28 members.

When opening accession negotiations with Ukraine and Moldova, the EU will nonetheless be likely to prompt its members to reflect on what institutional reforms might be necessary. But this process is unlikely to come to fruition until after the 2024 European Parliament elections. And there are ways of adjusting the body’s structure without opening up the complicated issue of revising its treaties, which the bloc is unlikely to do. EU countries and bureaucrats still vividly remember when they attempted to set up a constitution in 2004, only to have the treaty establishing it be rejected by referendums in France and the Netherlands, two of the original six member states. Most of the substance of that attempt was later rescued by the Treaty of Lisbon. But the appetite for enacting further treaty changes is still distinctly limited in Europe’s capitals.

There is certainly one structural problem the EU must address in order to admit Moldova and Ukraine: its budget and spending programs. Today, the EU budget amounts to roughly 1 percent of the combined GDP of member states. Although this is a fraction of their public spending, it still amounts to more than 1.2 trillion euros a year, or $1.26 trillion. The largest outflows of this money to member states are “cohesion funds” to finance economic convergence in the bloc’s poorest regions and agricultural subsidies under the EU’s common agricultural policy. Together, these two programs make up roughly two-thirds of the bloc’s budget.

Ukraine is substantially poorer than most EU states, and it is also a major agricultural producer. As a result, experts estimate that roughly one-third of the body’s current agricultural subsidies and one-quarter of its cohesion funds would end up going to Kyiv. If the EU’s policies did not change, Ukraine’s admittance would therefore force cuts in programs for present member countries, such as Poland (now the largest net beneficiary). It goes without saying that such a change would cause political turbulence.

The EU operates on a seven-year budget, so the body should start addressing these issues in the next one, which will have to be adopted by 2027. Thankfully, there is a template for what the bloc can do. Before the EU’s major enlargement in 2004, when many central European states joined, the body created a separate budget—in addition to the standard one—to take care of enlargement. The bloc will likely have to apply this model again.

There will be fierce political battles over these issues. Part of the solution will undoubtedly have to be lengthy transition periods until the new member states fully join the EU’s different programs. This was the case when both Poland and Spain, countries with roughly similar populations to those of Moldova and Ukraine, respectively, entered the union. EU leaders might also have to address fears in certain countries about the Ukrainian agricultural sector’s strong competitive position, although some analysts will be quick to point out that the country’s agriculture industry should instead be seen as a strong advantage, given that it would help the EU as a whole.

Agriculture is not the only domestic issue that might complicate accession. There are numerous ways in which a given country’s politics could derail the process. France has a presidential election in 2027, and the vote might empower politicians that are hostile to enlargement. Other states also have elections that could throw sand in the gears. Hungary could live up to its reputation as a spoiler, especially since it is already trying to block EU financial assistance to Ukraine. And as Serbia’s and Turkey’s experiences show, dangers can always arise from political developments in an applicant country.

Ukraine’s struggles with the rule of law and corruption will certainly figure heavily in the process. Given that Hungary and Poland both experienced democratic backsliding after entering, the EU will want to build in stronger safeguards to make sure that future members do not also become illiberal once they join the bloc. Yet Ukraine has made substantial democratic progress since independence, and it no longer has the billions of dollars in Russian gas money that once helped foster graft. Kyiv continues to struggle with corruption, but it is clearly fighting it.

BIGGER AND BETTER

For Ukraine, joining the EU is more than just a matter of stability. It is also a matter of its future prosperity. Becoming a part of the EU’s integrated single market and an adherent to its rules will foster more investment in the country, including in its factories. The result will almost certainly be strong economic growth, as it was in other post-communist states that joined the bloc. In 1990, when the Soviet empire was falling apart, the per capita GDPs of Poland and Ukraine were roughly the same. Today, Poland’s GDP per capita is more than four times as large. And although Poland quickly made impressive economic reforms, especially by comparison with Ukraine, it was EU membership that helped most.

The outcome of the war will certainly play a major role in Ukraine’s growth. But if the country can become secure, there is no reason why the EU cannot help it make a journey similar to Poland’s in the decades ahead. The EU, after all, has a history of great achievements: reconciling longtime foes in western Europe, anchoring democracy in southern Europe, and propelling reform and prosperity in central Europe and the Baltic states.

To be fair, the task ahead is probably harder than these achievements—perhaps the EU’s most challenging one yet. But it is also the most consequential. Russia is threatening the peace and stability of Europe, and bringing Moldova and Ukraine into the EU is critical to strengthening the continent’s east. That, in turn, will protect Europe as a whole.