At Vukovar the swift-flowing Danube is all that separates Croatia from Serbia. From midnight tomorrow this will also be where the EU meets the rest of the former Yugoslavia, a federation that just 20 years ago was tearing itself apart, killing well over 100,000 people and driving millions from their homes.

Croatia is about to become the EU’s 28th member, nine years behind Slovenia but well ahead of the other ex-Yugoslav states; only this week Serbia received EU approval to start accession talks that have been long delayed by the legacy of war. It’s a war that changed Vukovar forever.

Until 1991 Croatia was known for its wealth, for its cosmopolitan atmosphere and for the fine Baroque buildings that ran down to its busy riverfront.

It was one of most the prosperous cities in Yugoslavia thanks to a huge shoe factory that employed 23,000 people, from all over the country, and to the port that served cargo and passenger boats on the Danube. Back then, locals now recall with a kind of mystified pride, more than 25 ethnic minorities were represented in the town’s population of 45,000.

The world did not know much about the old Vukovar, sitting quietly on the fertile plains of eastern Croatia, deep in the sleepy provinces of what was once the Habsburg empire.

Most of the world learned about Vukovar from the war, which bequeathed new nicknames to this once-envied place – Croatia’s Stalingrad, Croatia’s City of Heroes – and a new term to the lexicon of human cruelty: ethnic cleansing.

This is the darkness from which Croatia has been running since the war with Serbia ended, in 1995. It has been running towards the EU, a union created to heal the wounds of an earlier European war and to prevent its members taking up arms against each other again.

But as Croatia prepares to join the club it finds that it cannot just slam the door on its recent past, and the prospect of EU membership seems only to have give it new life.

"There were about 20,000 protesters here from all over Croatia," says Suzana Agotic of the Nansen Dialogue Centre, which works to rebuild a multiethnic Vukovar. "Things are very polarised again here now. People say everything is going fine in Vukovar, but it's not."

Agotic describes how flag-waving war veterans, many wearing their old uniforms, led demonstrations this year against plans to erect street signs in Vukovar in the Serbian Cyrillic alphabet.

According to the 2011 census almost 35 per cent of Vukovar’s 27,683 residents are Serbs. By law, bilingual signs must be introduced anywhere that a minority comprises at least a third of the population. The bilingual signs have appeared in other areas of Croatia that have large Italian, Hungarian and even Serb minorities.

Opponents say Vukovar is a special case and should not be subject to the law, regardless of what Brussels says. "There's no way that we accept Cyrillic," Dragutin Glasnovic, a spokesman for critics of the move, said at one of the rallies. "Vukovar should be treated differently due to a special respect for its victims on which Croatia was founded."

Barbarous enemy
Around him protesters wear T-shirts bearing the slogan "For a Croatian Vukovar – No to Cyrillic" and banners reading "This is not Serbia". For them Serbian is the language of a barbarous enemy that besieged Vukovar for three months in late 1991.

A couple of thousand lightly armed Croats defended Vukovar from more than 35,000 Yugoslav troops, as Serb commanders pounded the city with tanks, heavy artillery and bomber aircraft. Barely a building was left undamaged, and families hid in basements as flying shrapnel and sniper fire menaced anyone who ventured out.

Twenty-two thousand people fled the city, and about 1,700 Croats were killed before Serb-led military and paramilitary groups finally overran the city, on November 19th, 1991. When they did, hundreds of people sought shelter in Vukovar’s hospital, from where they hoped to be evacuated.

Instead the Serbs transported about 250 wounded fighters and civilians to a pig farm at Ovcara, outside Vukovar, where they were beaten, tortured and shot dead. Their bodies were later found in a mass grave not far from the city. "Everyone knows what happened here in 1991," says Tomislav Josic, a war veteran who leads the Defence of Croatian Vukovar group in its drive to block the Cyrillic signs.

A lot of Croatian and foreign money has been spent on the reconstruction of Vukovar, and, as it becomes a border town of the EU, only a few of its facades bear the scars of the horrific siege.

“The place looks nice, there are new buildings, but scratch the surface and things aren’t so good,” says Ljubomir Mikic of Vukovar’s Centre for Peace, a rights and democracy group.

He explains that communal divisions start at nursery school, where most Serbs and Croats attend classes taught in their own languages, and tend to mix only with their ethnic kin.

“Children are taught to hate,” he says, “and the younger generation is not necessarily more open-minded and liberal than their elders. Some have taken on the wartime experiences of their parents and grandparents, even though they were not even alive then.”

With memories of war still fresh in many minds, employment scarce and political allegiances important in securing a job, people in Vukovar and other areas badly affected by the fighting are easily manipulated by politicians, Mikic adds.

“The messages sent by these protests are not encouraging,” he says. “The fight against Cyrillic is becoming the fight against the presence of the Serb minority. It’s the only card the nationalists have to play. After all, Cyrillic is nothing new here; it has been used in Vukovar for centuries.”

Zeljko Sabo, the conciliatory mayor of Vukovar, who has just been re-elected, is a figure who infuriates nationalists. "The citizens of Vukovar decided by a majority that they want a city of peace and tolerance, not a city of divisions . . . I will manage the city in favour of all its citizens," Sabo said recently.

The push to improve ethnic relations in Vukovar, and to strengthen ties with Serbia, has support from Croatia's president, Ivo Josipovic. "The EU is primarily for us a peace project," he tells The Irish Times.

Josipovic was with the then Serbian president, Boris Tadic, in Vukovar almost three years ago, when he became the first Serb leader to apologise for the massacre.

Tadic has since been ousted by the former radical nationalist Tomislav Nikolic, who, just before taking power, said Vukovar was "a Serb city and Croats have nothing to go back to there".

But Josipovic denies suggestions of a chill in relations between Zagreb and Belgrade. “We have good co-operation on a wide range of areas. And there has been no deterioration with Nikolic. Some of his statements are not helpful, but I think we can overcome this.”

Croatia has many obstacles to overcome as it finally joins the EU, from a stagnant economy and rising unemployment to often tricky ties with its neighbours.

But there is a feeling, in rebuilt Vukovar and elsewhere, that the future cannot be as bad as the recent past, and that the ethnic strife that killed Yugoslavia will not be allowed to infect the EU.

"No one expects miracles on July 1st. We know that Europe has plenty of its own problems now," says Marko Kovacevic, a Vukovar notary, walking beside the Danube during his lunch break. "Our region is much poorer than Zagreb or the coast, and young people are leaving. But they go because unemployment is high, not because of problems between Croats and Serbs."

Kovacevic’s family lost their house and an apartment when Serbs occupied Vukovar. His grandfather was killed and dumped in a mass grave. It is not an uncommon story here.

“It’s much harder for the older people to move on, because they really suffered and fought in the war. But I have Serb friends, and we all have to move forward. Life goes on,” Kovacevic saxys, while behind him the Danube flows on between its Croatian and Serbian banks. “A Serb of my age would tell a different story. He would have had his own suffering. Every page has two sides.”