The European Union’s task of enlargement remains starkly incomplete: the bloc’s south-eastern flank is largely in limbo. Almost 20 years after the Balkans wars ended, there’s a gaping hole on the map, bounded by members including Croatia, Romania and Greece. In 2015, the refugee crisis exposed how swiftly nationalist passions could return to the region. As hundreds of thousands of people trekked northwards, volunteers helped provide food and clothing to desolate refugees. But tensions flared among governments, and troops were even deployed at some borders. Two years on, the Balkan route is mostly closed, but the region’s problems are still vivid.

The question of how to stabilise the Balkans, anchor democracy there, and bring the region closer to EU institutions remains an immense challenge, given insufficient attention. Balkan civil society activists are increasingly concerned about unemployment, corruption, and a brain drain as young, educated people leave for jobs elsewhere in Europe. They say it is crucial to reboot the prospect of EU membership for Serbia, Bosnia, Macedonia, Albania and Montenegro, to encourage much needed reforms. They are right. The Balkans matter to Europe not just because of the migration issue, but also for energy routes, security, and the fight against organised crime. Little has been done to address underlying problems.

The good news is that awareness of this seems to be growing. The president of the European commission, Jean-Claude Juncker, said recently that if the EU wants to ensure more stability in its own neighbourhood, “then it must maintain a credible enlargement perspective for the western Balkans”. In 2018, the UK is due to host a special summit on the western Balkans – an initiative presented by the government as evidence that “Britain is leaving the EU but not Europe”. And when the French president, Emmanuel Macron, laid out his plans for Europe’s future, he said that “the EU will have to open itself up to the Balkan countries” once they meet the conditions, because that will help consolidate “peace and stability on our continent”. At stake, he added, is the need to prevent Balkan nations from “turning their backs on Europe and moving towards either Russia or Turkey, or towards authoritarian powers”.

For the Balkans question is as much about broader international competition as it is about values. The EU is confronted with strong competition from external powers seeking to secure footholds on its doorstep and capitalise on the region’s weaknesses. Russia plays on orthodox and Slavic ties, and Turkey seeks to promote a “neo-Ottoman” vision. But more distant actors, including China and Saudi Arabia, are increasingly active. One civil society activist in Belgrade describes this as “an unbelievable geopolitical game that would have been unimaginable in 1989”, when the communist bloc started crumbling.

As the EU speaks of reinvigorating its 60-year-old project, it needs to build a stable regional architecture for the Balkans. Years of deferring the prospects of membership have taken a toll. Studies show public support for the EU has dropped among the region’s citizens. This only helps fuel polarisation and populism, with corrupt regimes benefiting and the economy suffering. Normalising the relationship between Serbia and Kosovo hinges on what Europe can offer. More EU funds should be directed towards the region as enticement.

Churchill once said that “the Balkans produce more history than they can consume”. If left unaddressed, bad governance and old feuds could backfire on everyone. The consequences would be felt beyond the region. The lesson from its history is surely that the rest of Europe has a key interest in making sure the Balkans are not left to become a backwater simmering with tensions, but are helped to modernise, and are one day brought into the club.