The arrest of Ratko Mladic offers hope for the survivors of the 1992-95 Bosnia war and for Serbia.
For those who lived through the war, Mladic's coming trial at The Hague is a chance for justice. For Serbia, there is the prospect of a fresh start as a member of the European Union.
Serbian President Boris Tadic has linked Mladic's arrest with Serbia's EU aspirations, and was equally explicit about his expectations of a favourable response, saying the arrest would give "new impetus" to Serbia's EU accession.
Notwithstanding the EU's currently fragile condition, membership remains a powerful lure to many states, particularly those in the western Balkans, but with a number of countries clamouring to fulfil the conditions imposed by the EU, including those required by the Copenhagen Criteria, the EU must be careful it is not offering something it cannot give, or is unwilling to give.
Amid the positive noises welcoming Mladic's arrest, some have evinced caution about Serbia's chances. It is unclear to what extent the EU will want to enlarge its membership, especially at a time of economic precariousness.
In any case, Serbia still has reforms to make to meet the accession criteria, and it continues to refuse to recognise Kosovo as an independent state. Tadic may have to decide whether he is willing to sacrifice Serbia's asserted sovereignty over Kosovo, as well as Mladic, for EU membership - something he has refused to consider in the past. For all the rhetoric, Mladic's arrest may not be as decisive a factor as Tadic expects.
Serbia is not the only aspiring EU member whose membership has been conditioned on the resolution of an internationally significant issue. To its east, Turkey has been trying to join the EU for decades, and has been in accession negotiations since 2005. It has implemented economic, political and judicial reforms to meet the Copenhagen Criteria, including attempts - albeit not very successful - to improve its human rights record.
However, much has been made of one problem preventing Ankara from joining: Turkey's illegal occupation of northern Cyprus, and its refusal to recognise the Greek Cypriot government, which has been a member of the EU since 2004.
Turkey's proposed entry to the EU is controversial for other and perhaps less politically correct reasons - its membership might be strategically beneficial, but its large population, widespread poverty and cultural dissimilarity are seen as ill-suited to the EU's rationale and its borderless Schengen zone. But Cyprus has been the main sticking point in Turkey's quest for accession.
With the UN's latest attempt at Cyprus negotiations under way, Europe has made it clear Turkey has no hope of entering the EU without a resolution of the issue. The UN special envoy to Cyprus, Alexander Downer, put it in stronger terms earlier this month, telling the Turkish Cypriot media the reunification of Cyprus could be "a development which will guarantee Turkey's accession into the EU".
While such hyperbole might serve a tactical function, it is important it not be empty, and that these sorts of outstanding political issues are not a mere cover for EU reluctance. Even if it were to meet all its accession conditions, is there really a chance that Turkey - so large, so poor, so "different" - would be embraced by the EU? Such rhetoric risks raising expectations which, if unfulfilled, will lead to resentment and anger.
In Serbia, Mladic's capture has sparked off mass protests by Serb nationalists, who regard him as a war hero, and his arrest and extradition to The Hague as a betrayal. That it was done under outside pressure and in aid of EU membership - however uncertain - would only heighten those sentiments. On the other hand, you can only imagine the backlash in Serbia, and in the western Balkans generally, should Tadic's actions not lead to Serbia's accession to the EU.
Mladic's arrest might sound like a fairytale ending for the EU - a triumph for the potential of "soft power" to persuade countries to democratise, bring war criminals to justice and settle long-standing disputes.
But it is questionable whether the EU is seeking another kind of fairytale ending - one in which the EU, after dangling the "carrot of accession" in front of a country, and leading it through numerous mazes without any genuine commitment, can take the carrot away with no repercussions.
That fairytale does not exist - and in such a case, neither should the carrot.