Author: Piotr Maciej Kaczyński

Poland’s evolving stance on the European Union’s future highlights its balancing act between EU treaty reform and enlargement ambitions, with a particular focus on integrating Ukraine. Amid the call for deeper integration, Poland faces internal tensions over sovereignty and seeks a pragmatic EU that reinforces security and regional stability without jeopardizing its national interests.

Ukraine’s future membership in the European Union is bringing divisions among EU political actors. Both the European Parliament and the European Commission have called for changes to EU treaties. Multiple governments have responded that there should be no opening of the EU’s constitutive documents, while others support amending them. Some member states are wary of further EU eastern enlargement and have formed a new “Atlantic group.” Portugal’s prime minister at the time, and incoming European Council President, Antonio Costa, noted that the Atlantic countries are concerned about the EU’s “center of attention […] shifting to the center of Europe.” German Chancellor Olaf Scholz, echoing his coalition agreement, has made his support for Ukraine’s EU enlargement conditional on EU treaty change. Amid multiple continental crises (economic, social, security, health, and migration), a significant shift of power in Warsaw in fall 2023 has also impacted the balance within the European Council. What are Warsaw’s considerations for the future of Europe on the eve of its Council presidency in early 2025?

To fully comprehend Poland’s stance on EU treaty reforms, it’s essential to understand the bilateral relations between Poland and its large Eastern neighbor, Ukraine. Ukraine is at the forefront of the next wave of potential EU enlargements. It’s widely accepted that the accession of the Balkan countries, as well as Moldova and Georgia, would not substantially impact how the EU operates, provided each country addresses critical issues like the recognition of Kosovo, corruption, border disputes (e.g., Transnistria, Abkhazia, and South Ossetia), and minority rights (a particularly significant concern for Bosnia and Herzegovina).

Yet Ukrainian membership would have major economic implications for the EU, affecting its single market, industrial policy, climate goals, agriculture, and the cohesion fund. These internal policies would need to coincide with re-evaluating security and foreign policy, particularly toward Russia. Ukrainian membership would likely also impact EU relations with Turkey in the Black Sea, transforming it almost into an “internal sea,” similar to the Baltic Sea.

This report is divided into three sections: the first examines Polish-Ukrainian relations in the current security and political context, the second reviews the EU treaty reform debate, and the final part explores the connections between Ukrainian enlargement and the need for treaty reform.