On January 16, representatives of Serbia and Kosovo met in Brussels for confidence-building talks. But, on that same day, the Kosovo Serb minority leader Oliver Ivanović was shot dead in the Serb-administered section of Mitrovica, in Northern Kosovo, and the talks were called off.

Since the end of the Kosovo War in 1999, the Western Balkans have made much progress in facing down the nationalist and reactionary forces that gave rise to that brutal ethnic conflict. But Ivanović’s assassination, most likely at the hands of criminal gangs that have been allowed to prosper in Northern Kosovo, now threatens to throw fuel on a still-smoldering fire. The region’s nationalist ghosts are being roused from their slumber.

Western Balkan countries are struggling to confront many other challenges as well. Corruption is rife, owing to organized-crime networks that grew out of the communist-era security apparatus. The influence of the United States in the region is declining, even as Russia becomes more revanchist. And, for most of the region’s countries, a big question mark hovers over the path to European Union accession.

That needs to change. Macedonia (provisionally known as the former Yugoslav Republic of Macedonia, or FYROM) has been a candidate for EU membership since 2005, yet accession negotiations have not gotten off the ground. Greece has always promised to veto Macedonian membership, owing to a dispute over the country’s name. And the country itself has long been split over domestic issues concerning corruption, abuse of power, and ethnic minorities.

Still, there is reason for hope. At the World Economic Forum’s annual meeting in Davos, Switzerland, this year, Macedonian Prime Minister Zoran Zaev met with Greek Prime Minister Alexis Tsipras and agreed to rename his country’s largest airport. Its current name, commemorating Alexander the Great, has long irked the Greeks.

For its part, Montenegro was accepted as a NATO member in June 2017. But it has also had to deal with increasing Russian influence, including an alleged plot to topple the current government. Montenegro, along with Serbia, has begun the EU accession process, but it still has a long way to go. Of the 35 chapters of EU law that must be negotiated, Montenegro has opened 30 and provisionally closed three. Serbia, meanwhile, has opened twelve and provisionally closed two.

Many other countries remain blocked altogether, either by vetoes from within the EU, or by domestic hurdles. Bosnia and Herzegovina, for example, is still wrestling with the constraints of the Dayton peace accords. And Milorad Dodik, the Kremlin-backed leader of its constituent Serb Republic, Republika Srpska, has been toying with the idea of a referendum on independence.

Russia clearly has an interest in discouraging Western Balkan countries from pursuing NATO and EU membership, which is all the more reason for the EU to step up its engagement in the region. To that end, EU Commission President Jean-Claude Juncker, in his “State of the Union” address last September, called for a “credible enlargement perspective” for the region. And in February, the European Commission plans to adopt a new “Enlargement Strategy,” which will set a target date of 2025 for the accession of Serbia and Montenegro.

But if such a strategy is to succeed, it will have to be accompanied by European-led reforms in the Western Balkans that align those countries more closely with EU membership requirements. Moreover, the EU must make clear that accession ultimately will be based on merit, and that target dates are aspirational, not binding. As the accession of Romania and Bulgaria showed, when arbitrary target dates are accorded too much weight, they can be counterproductive, because they weaken the incentives for meaningful reform.

The EU’s Enlargement Strategy will require support from individual EU member states, which should be reminded that failure to keep the Western Balkans within the European fold could result in a return to the bloodshed of the 1990s, or worse. It will also demand support from European partners and allies – particularly the US – which should be reminded of the geopolitical importance of avoiding such an outcome.

As for the region itself, political elites will need to be motivated to pursue necessary reforms, rather than putting their own economic interests first. The highest priority should be judicial reforms, which will help these societies internalize the rule of law, and regional reconciliation, without which there can be no progress toward accession. Beyond these fundamental imperatives, the region will also need massive investments in transportation and communications infrastructure, to connect it to the rest of Europe, rather than to China and Russia, as has been the trend in recent years.

The alternative to European engagement in the Western Balkans is rising nationalism and a possible return to violent conflict. The EU must do everything in its power to forestall that scenario.