President of Bosnia and Herzegovina's entity Republika Srpska Milorad Dodik casts his vote | Elvis Barukcic/AFP via Getty Images Bosnian Serbs challenge Dayton order in referendum ‘It’s a political adventure we did not need,’ said Bakir Izetbegović, Bosniak member of tripartite presidency.

BANJA LUKA — Bosnian Serbs voted on Sunday in a referendum that could be the boldest challenge to date to the constitutional order, created by the Dayton Accords which ended the war in 1995.

Milorad Dodik, the president of Republika Srpska has been threatening since 2006, when he came to power, to hold referenda on questions ranging from territorial separation of the Serb entity to the authority of Bosnian state judiciary, which many Serbs see as biased, and the national holiday. His party's platform includes an explicit threat to hold a referendum on independence in 2018.

The question on the ballot of Sunday's non-binding vote was: "Do you approve of January 9 as the day of the Republika Srpska?" Few 'no' votes are expected.

The date marks the 1992 declaration of independence by Bosnian Serbs just before the devastating war was unleashed, resulting in 100,000 dead, a million displaced and a genocide against Muslims in Srebrenica, Europe's worst massacre of civilians since World War II.

Defying highest court

Bosnia's Constitutional Court banned the vote on September 17 on the basis that it discriminates against non-Serbs. While more than 80 of the court's rulings have not been implemented in the past, until Sunday's referendum in Republika Srpska, no collective body in Bosnia had ever directly defied an order of the court.

"If we retreat now, next year they will revoke the name of the Republika Srpska” — Milorad Dodik

"I urge you to vote on the referendum and defend our statehood day and our freedom," Dodik said on Saturday in eastern Sarajevo. "If we retreat now, next year they will revoke the name of the Republika Srpska."

The vote was strongly condemned by the international community and Bosnia's Muslim majority, known as Bosniaks. They said it was illegitimate and unlawful, an intentional attack on Bosnia's fragile institutions as the country tries to tackle stagnant economy, high unemployment and move closer to the European Union.

"It's a political adventure we did not need," said Bakir Izetbegović, the Bosniak member of the country's tripartite presidency. Speaking on Thursday to Al Jazeera Balkans during the United Nations General Assembly meeting in New York, Izetbegović said the referendum is part of Dodik's ambition to eventually ask residents of Republika Srpska to breakaway.

He warned that the Serbs "can not take for themselves something that belongs to all, and bring down the Dayton agreement and peace with it."

While some have sounded the alarm on the referendum as a source of deepening tensions, a step closer to a territorial break along ethnic lines and even armed clashes, the streets of Banja Luka, the Bosnian Serb capital, appeared much like any Sunday with citizens far more interested in shopping and socializing in outdoor cafés than politics.

Return to the 1990s

There was also fear that the nationalist rhetoric during the referendum campaign could reignite conflict.

"This campaign has brought us back to the 1990s" — Ramiz Salkić

"This campaign has brought us back to the 1990s," said Ramiz Salkić, the Bosniak vice-president of the Republika Srpska. "People are worried and horrified because the wounds of the past are still open." Bosniaks and Croats, who make up some 20 percent of the population of the Republika Srpska, are largely staying away from the polls.

"This is a unilateral redefinition of the Dayton Accords," said Reuf Bajrović, the Bosniak head of a new civic political party in Sarajevo. "If Dodik can redefine Dayton without consequences, this will become the norm.

"Dodik is banking on no reaction," says Bajrović. "I think it's a good bet."

The U.S. Embassy in Sarajevo condemned the referendum, saying in a statement that Dayton "cannot be challenged without consequences." They did not give details on the consequences.

"This referendum is encouraging the unraveling of Dayton but the Republika Srpska government is not solely responsible," said Miloš Solaja, a political scientist at the Center for International Relations in Banja Luka.

"Our constitution is part of an international settlement, it is not our constitution," he said, adding that the three of the court's nine judges are internationals. Solaja blamed the international community for heightened ethnic tensions in Bosnia because they failed to ensure equal treatment for the country's three constituent nationalities: the Serbs, Croats and Bosniaks.

Critics at home see the referendum as an emotional diversion from the low quality of life in the Republika Srpska: unemployment is at 35 percent, monthly wages average at €430, among Europe's lowest, while international isolation and political stagnation prevail.

Even Moscow is silent

A decade of empty referendum threats has worn out Dodik's credibility. The timing of the poll is also connected to the local elections scheduled for October 2. Dodik's aggressive posture is widely expected to strengthen his party's position.

"We are going through a useless political game," says Branislav Borenović, an opposition MP in the Serb entity. He admitted that the opposition has been forced to support the referendum to maintain its position in next week's elections.

"We have spent six months dealing with this court decision. Why doesn't anyone talk about what is happening with the economy, health care, the pension system and agriculture?"

Dodik's push has increased his international isolation with the international community — minus Russia — opposing the referendum. He went to Moscow on Thursday to talk to President Vladimir Putin, but at the end, even the Kremlin appeared to distance itself, releasing a short statement on the meeting without mentioning the referendum.

Even Serbia, currently negotiating for EU membership, has backed away in an effort to minimize a risk of confrontation.

Political analyst Stefan Blagić from Frontal.ba expects the Republika Srpska parliament to follow the Constitutional Court decision and the referendum result simultaneously by drafting legislation declaring January 9 to be something like a national celebration and not an "obligatory" national holiday.

"Regardless of the damaging impact this exercise has already had on political discourse and the already fraying social fabric, we are witnessing an exercise in which an election-like process is being implemented and abused in a legal and procedural vacuum," according to the analysis of the Democratization Policy Council, a transatlantic think tank with a long-time presence in the Balkans.

Croats want their slice

The Central Election Commission in Sarajevo refused to share the official electoral list with Banja Luka. The entire poll is overseen by Republika Srpska government bodies, with no external or independent monitors or vote-counters. But few observers in Banja Luka seemed concerned since the "yes" result was a foregone conclusion even before the vote started.

For their part, Bosnian Croats also feel disadvantaged since their electoral territory includes significant numbers of Bosniaks. The referendum is expected to embolden long simmering ambitions of Croats for either a de jure third territorial entity or an equally disruptive "de facto" third entity uniting non-contiguous Croat populated areas into one electoral unit.

"Because there is no meaningful reaction by the guarantors of the Dayton Peace Agreement it demonstrates that this disintegration trajectory is accelerating," said Kurt Bassuener, an analyst at the Democratization Policy Council.

Bassuener said that Bosnia's entropy will increase since "now everyone with an unfulfilled agenda will start pursuing it with a decreasing lack of restraint because there is no resisting force."