The EU accession countries of the Western Balkans (WB6) have come a long way since the wars of the 1990s. Besides progress at the individual country level, the emphasis within the EU accession framework upon regional cooperation and good-neighbourly relations has contributed to an overall strengthening of relations between the WB6 and their EU neighbours. Nonetheless, the persistence of unresolved bilateral disputes – some open, some only potential – poses a real risk of renewed instability by delaying EU integration and distracting from domestic reforms. It is therefore crucial that on-going international engagement with the region focus on tackling outstanding bilateral issues, both in their own right and in view of removing potential obstacles in the countries’ path towards EU entry.