The European Union gave Serbia the status of candidate for membership on Thursday in an attempt to promote better government in the western Balkans as the region struggles to emerge from the wars of the 1990s.
EU leaders took the decision at a summit in Brussels, launching a potentially lengthy process to bring the former Yugoslav republic into the bloc.
It marks a turnaround for Serbia, once seen as the pariah of Balkans for its central role in wars that followed the collapse of Yugoslavia under the leadership of Slobodan Milosevic.
They have done a lot, and the pro-European forces in Serbia need a sign that Europe sees what they have done and listens to the will to become part of Europe, Swedish prime minister Fredrik Reinfeldt said before the meeting of EU leaders.
Becoming an EU candidate rewards years of political reform and improvements in relations with Kosovo, a former Serbian province, as well as Belgrade's efforts to come to terms with its past by catching war crimes suspects.
The EU aims to commit Belgrade to the bloc's democratic values and ensure that ethnic tensions do not again spark violence in the region, scene of Europe's most devastating fighting since World War Two in 1990s.
The EU is gradually dismantling the Balkans-shaped bomb lying right next to it, said Daniel Korski, senior analyst at the London-based European Council on Foreign Relations.
The Balkan wars marked a failure by the EU to stop violence in its backyard. During the Serb assault on Bosnia, tens of thousands of people died and a million lost their homes in four years before NATO troops swooped in to force the Serb army out.
More than a decade after the fighting subsided, the EU is accelerating its embrace of former Yugoslav states, which started when Slovenia joined the bloc in 2004.
Croatia last year earned the nod to become the EU's 28th member in July 2013. Kosovo, which declared independence from Serbia in 2008, a move Belgrade still refuses to recognise, is also establishing closer political and trade links with the EU.
But much of the western Balkans suffers from political deadlock and ethnic rivalries, while corruption and organised crime are rife. Part of the EU plan is to send the message that it pays to follow EU guidance.
Croatian membership and Serbian progress will concentrate minds across the region, said Korski. They will think: 'If we take reform seriously, we will get invited. If we don't, we get nothing'.
(Additional reporting by David Brunnstrom)