The slaying of Kosovo Serb politician Oliver Ivanovic on Tuesday put a spotlight on new tensions in the Balkans, years after a violent conflict divided the region. Considered a moderate politician, Ivanovic was reportedly shot several times near his office in Mitrovica, a Serb-run city in northern Kosovo.

His death had immediate repercussions, as political talks in Brussels between Kosovo Albanians and the Serbian government were interrupted. Almost 20 years after the Muslim-majority state broke with Serbia and nearly a decade after it declared independence, strain between the two has again intensified and could be further fueled by Tuesday's suspected murder.

Why is Ivanovic's suspected murder so far-reaching?

“He was a voice of moderation and a voice of dialogue,” said William Nash, a former U.N. civilian administrator in Mitrovica who worked closely with Ivanovic shortly after Serbia withdrew its troops from the region. Nash described Ivanovic as a personal friend. “I was there for about eight months. And throughout that time, Oliver was smart and articulate, but also pragmatic,” Nash said in a phone interview.

A key negotiating partner during NATO-E.U.-led talks, Ivanovic was sentenced to nine years in prison in 2016 over alleged war crimes committed against ethnic Albanians in the late 1990s. However, the verdict was later overturned, and Ivanovic continued to dispute his involvement.

After a violent conflict in the region began in 1998, NATO decided to bomb Serbia a year later, eventually forcing the Serbian government to withdraw its troops. The United Nations administered Kosovo in the years after the conflict ended, working with Ivanovic and other Kosovo Serb politicians, even though Serbia never officially recognized Kosovo's independence.

Today, Kosovo remains ethnically split — a situation that has become especially apparent in Mitrovica, a city that is run by Kosovo Albanians in the south and by Kosovo Serbs in the north and is where Ivanovic worked. That is why Serbia views his suspected murder as a terrorist attack targeting its sovereignty, even though it is unclear who was behind it.

Ivanovic was a strong advocate of efforts to reconcile the two nations, and both sides now fear his death will complicate efforts to achieve that goal.

Why are tensions on the rise?

Tensions never fully disappeared but have become more pronounced since January 2017, when Serbia sought the arrest and extradition of then-former (and current) Kosovo prime minister Ramush Haradinaj from France. Although Haradinaj has been cleared by a U.N. tribunal, he is still sought on war crimes charges in Serbia, and his arrest revealed the continued presence of old rifts. France refused to extradite him.

Days after France refused to extradite him, Serbia attempted to establish a train connection between its capital, Belgrade, and the ethnically divided city of Mitrovica. Authorities there stopped the train — which bore the slogan “Kosovo is Serbia” — before it was able to enter Kosovo, saying the initiative constituted a provocation. Kosovo fears Serbia may be trying to annex the Serb-majority region in the north.

“It is the Crimea model,” Kosovo President Hashim Thaci told Reuters at the time. Even though Serbian officials denied the accusations, deep divisions remain endemic in the region, especially in Mitrovica, as my colleague Nicole Crowder noted in 2015:

The Albanian majority in the southern part of Mitrovica has long hoped for Kosovo’s independence but continues to struggle with the resulting economic and social problems. The initial euphoria that accompanied the founding of the Kosovo state in 2008 has shifted to a general skepticism in the face of the political stalemate.
In the Serbian section, a sense of instability is omnipresent. Serbs oppose the establishment of an independent Kosovo state because they perceive Kosovo to be the very heart of Serbian history and culture. The Serbs in Mitrovica, however, are afraid of being abandoned altogether by the government in Belgrade, which they believe to be focused on its effort to become a member of the European Union.

What are the international implications?

Russia is among the countries that have refused to officially recognize Kosovo as an independent nation, and it continues to back the Serbian government.

Since the inauguration of President Trump there have been mounting fears in Kosovo over a possible Russian-backed Serbian annexation of the country's ethnically Serbian enclave in the north. Kosovo's government believes Trump's pro-Russian attitudes may embolden the voices of those in Serbia who seek military action.

Ivanovic's determination to prevent such a scenario, according to Nash, his former colleague and friend, was particularly evident during a visit he made to Berlin after NATO's intervention in the conflict. In Germany, the Kosovo Serb politician examined how a once-divided city was gradually growing together.

His death Tuesday has made a similar reconciliation in the Balkans less likely.

More on WorldViews: