June 18, 2026.

Published by the Clingendael Institute in June 2026, this article by Wouter Zweers examines current debates on adapting the European Union’s enlargement policy in response to the prospect of potential new memberships. Based on several “non-papers” suggested by France, Germany and the Benelux countries, it examines the different perspectives on the integration of candidate countries and the reforms needed within the EU.

The analysis highlights two approaches. The first prioritises the gradual integration of candidate countries through increased participation in European policies and institutions prior to accession. The second focuses more on managing the risks associated with enlargement, particularly through extended transition periods and strengthened safeguard mechanisms.

This publication advocates an approach to enlargement based on a more concrete and ambitious form of European integration. Many of the EU’s problems today are internal and exist regardless of whether new countries will join the EU. From this perspective, EU enlargement and reform appear to be two complementary processes that are necessary to strengthen the effectiveness and legitimacy of the European Union in the context of current geopolitical challenges.

You can find the article “Challenge accepted? EU Enlargement non-papers provide mixed picture of EU integration commitment” authored by Wouter Zweers and published by Clingendael Institute here.