Kosovo police officers in gas masks inspect parliament after opposition lawmakers launched tear gas during the first legislative session of the year in February. (Armend Nimani/AFP via Getty Images)

Smoke, shouting, chaos and tear gas are the staples of a riot — or an assembly session in Kosovo. It has become common for opposition parties in this western Balkan state to delay votes through the use of tear gas and other obstructionist tactics. It happens so often that the government had to get more powerful metal detectors and augment the building’s ventilation system.

Why? Because of Kosovo’s contested border with Montenegro. Of course, border conflicts around the world can be violent. But unlike most border conflicts, this one is between political parties within the same country.

Kosovo is the last of the former Yugoslav states to gain independence. After 10 years of ineffectual pacifist protest in the 1990s, Kosovo fought a war with Serbia from 1998-1999. That war ended when NATO intervened and bombed Serbia. After 10 years of international supervision under the United Nations Mission in Kosovo (UNMIK), Kosovo, backed by the United States, unilaterally declared independence from Serbia in 2008. Serbia has not recognized Kosovo, but both Kosovo and Serbia aspire to membership in the European Union.

Now, as a condition of its visa liberalization agreement with the European Union, Kosovo needs to clarify its border with Montenegro, which separated from Serbia in 2006. In exchange, the E.U. will allow Kosovo’s citizens to legally travel to E.U. countries for medical care, education and business. Because Montenegro used to be part of Serbia, establishing this boundary is the first step in clarifying the borders of the new state. The more difficult next step will be clarifying the boundary with what is now the state of Serbia.

Where does Montenegro begin, exactly?

At issue is whether the boundary with Montenegro is near the foot of the Prokletije Mountains or higher up, along the ridgeline. The Prokletije Mountains, often translated as the Cursed Mountains or, more ironically, the Damned Mountains, divide Kosovo and Montenegro.

Many experts have found that the border at the foot of the mountains is accurate, because it is consistent with the findings of the Kosovo Cadastral Agency, the government mapping authority, and maps of the old Yugoslav boundaries between the two regions. Most members of the ruling party, the Democratic Party of Kosovo (PDK), support the proposed boundary at the foot of the mountains, which is the result of an agreement signed Aug. 15, 2015, between Kosovo and Montenegro. The border agreement was not controversial in Montenegro, which has friendly diplomatic relations with Kosovo.

However, the Kosovo opposition parties Alliance for the Future of Kosovo, which draws its support from the area of the country along the Montenegrin border, Vetëvendosje, and the Initiative for Kosovo object to drawing the boundary at the foot of the mountains. They claim that the documentation is flawed and that the borders of the state were reduced during the conflict with Serbia — and insist that the boundary is further up into the mountains.

Where else do you find tear gas inside parliament?

This would all just be entertaining political theater if the stakes were not so high.  The border demarcation has been one of the justifications for violent anti-government demonstrations by supporters of the opposition parties. These protests have plagued Kosovo in 2016 and have interrupted the government’s ability to function for nearly six months.

Meanwhile, the postwar economy stagnates as Kosovo struggles with its transition out of socialism. The unemployment rate for 15- to 24-year-olds is at 55 percent. Not surprisingly, illegal migration from Kosovo to other parts of Europe has surged as young people look for work they cannot find at home. Visa liberalization and further integration into the European Union would help Kosovo’s economy — but cannot be achieved until the border is drawn.

Nationalism propelled Kosovo’s 10-year pacifist struggle for autonomy and its war for independence. When land has been hard-gained, a new state’s citizens can find it difficult to tolerate territorial loss. The border demarcation was supposed to come to a vote on Sept. 1, but the government withdrew the bill, presumably because members of the PDK have been convinced by the opposition protests — and because it would not have passed.

Clear borders prevent war. But trying to define those borders can start one.

Political scientist Andrew Owsiak has shown that once states settle their borders, they are less likely to go to war with their neighbors. But there’s a catch: When new states try to draw those boundaries, they are at risk for erupting into war.

From 1998 to 2000, Ethiopia and the new state of Eritrea fought a brutal border war, resulting in tens of thousands of deaths, over the Badme Triangle, a tiny area of scrubland with a single small town. Skirmishes around Badme still occur. More recently, Sudan and the brand-new state of South Sudan have been fighting over the ill-defined border in the Abyei region.

Many observers like to believe that creating a new state can end violent civil war. But as these examples show, drawing borders can instead be the spark that re-ignites conflict.

Unlike in these conflicts, Montenegro never fought Kosovo; rather, both countries separated from Serbia. But drawing that border is just the first step in a far more complicated endeavor. At some point, Kosovo will have to officially mark its border with Serbia — despite the fact that Serbia still does not recognize Kosovo and relations between the two states are tense. If defining the border with Montenegro is setting off this much civil unrest, then peace will surely be shaky when the time comes to mark the border with Serbia.

Sandra Joireman is the Weinstein Chair of International Studies and professor of political science at the University of Richmond. She studies property, law and post-conflict return migration.

Correction: An earlier version of this post inaccurately referred to the Prokletije mountains as the “Shar” mountains, and said implied that Montenegro “seceded” rather than “separated” from Serbia, into which it had never formally been incorporated after the dissolution of Yugoslavia. The Monkey Cage regrets the errors.