Twenty years after Nato ground troops first entered Kosovo at the end of a 78-day aerial bombardment, 3,500 troops from the military alliance remain on the ground in the fledgling nation where the conflict is still yet to be definitively settled.

Today, the 28-country Kosovo Force (Kfor) acts largely as a “third reserve” after the local police and the EU, although there is one exception where Nato troops guard the 14th-century Serbian Orthodox monastery at Dečani.

Nato troops patrolling the streets are largely unarmed community liaison teams, doing low-key work that involves testing the temperature of the local community in the capital, Pristina, and other main population centres. At Dečani, where the Serbian monks say they need the protection of the soldiers from a hostile municipality, the most recent incident was in 2016, when four armed Islamists were arrested outside the monastery.

It is slow-paced work and prompts questions as to its wider purpose. “Twenty years is a long time for a peacekeeping mission,” a soldier on the ground discreetly observed when asked about their task.

It is not an isolated opinion. The US, which contributes the largest contingent of troops – about 600 – is understood to have seriously considered downgrading its presence.

A senior western official said: “Withdrawal would be crazy. Over in Serbia, they count the troop numbers. This is a country of 1.8 million moderate Muslims. After Afghanistan and Iraq, we need a result. This could be a real strategic win for us.” Confronted by such arguments, the US has decided to leave troop numbers unchanged – for now.

Western attention remains fitful. The UK contributes 30 troops – despite historical engagement in a country where several children are named Tonibler after the then British prime minister, Tony Blair, who with the then US president, Bill Clinton, led what was seen at the time as a popular military intervention. France sends none.

Nato’s intervention in 1999 began with an air campaign against Serbia, only the second time the alliance had been engaged in military action since its inception in 1949 – the first being in Bosnia, also against Serb forces.

It followed a growing period of violence between the secessionist Kosovo Liberation Army (KLA), representing a majority of the local Muslim population, in what was then part of the rump of Yugoslavia, and Serbian forces, representing the majority in the country overall.

The power of the western bombing forced the withdrawal of Serbian forces in June 1999. Fifty thousand troops, led by Britain’s Sir Mike Jackson, entered to the jubilation of Kosovan Albanians.

Sir Mike Jackson in Pristina in 2000. Photograph: Hazir Reka/Reuters

Nearly 10 years later, independence was declared, although Serbia and Russia still do not recognise the country and recently helped prevent it from joining Interpol.

A total of 13,517 people were killed or went missing during the Kosovan war, between January 1998 and the end of 2000, each of whom is documented by the Humanitarian Law Center in Pristina. Of these, 10,415 were ethnic Albanians; 2,197 were Serbs.

Bekim Blakaj, the executive director of the NGO, argues a proper historical record is needed to counter the “national narratives” that are emerging. “We are trying to create a collective memory about the war,” he said.

Kfor soldiers guard a border crossing between Serbia and Kosovo in 2011. Photograph: Sasa Djordjevic/AFP/Getty Images

“The Serbian side is trying to deny crimes committed by them, and the same thing is happening here. In Kosovo, you can only hear about Albanian victims, not about non-Albanians.”

A new exhibition in three rooms in the basement of Pristina’s library is dedicated to the 1,133 children who were killed or went missing, and features items belonging to them, including a backpack with a Bayern Munich logo containing schoolbooks used by one victim, Altin, a fourth-grade pupil, on the day he was shot by Serbian forces.

No final peace deal has been struck between Serbia and Kosovo, whose president, Hashim Thaçi, is a former commander in the KLA. Tentative peace talks involving a possible land swap – where Kosovo would have given up territory in the Serb-majority north in return for Serbian lands elsewhere – went nowhere last year because the idea was unpopular in both countries.

Separation between the two communities today is at its sharpest in Mitrovica, in the north of Kosovo, where they are separated by a bridge spanning the Ibar River, with Albanians largely to the south and Serbs to the north. Despite EU-funded renovation, it remains closed to traffic, blocked by the Serbian minority administration in the north, although open to pedestrians.

The bridge over the Ibar in Mitrovica. Photograph: Pierre Crom/Getty Images

Late last month, there was a brief upsurge in tension, when Kosovan police made a number of arrests around the country aimed at tackling corruption and organised crime elsewhere in the force. Arrests of ethnic Serbs prompted locals to put up an informal roadblock.

Four police officers were injured trying to clear it, a Russian official working for a UN agency was briefly arrested, and the Serbian president, Aleksandar Vučić, put his country’s troops on full alert. Although the situation was defused within a couple of days, regional diplomats worried the episode had set back Kosovan-Serbian relations for months.

A Kosovan police officer keeps a lookout near Mitrovica after an operation met resistance. Photograph: Armend Nimani/AFP/Getty Images

Gen Lorenzo D’Addario, the Italian who commands Kfor, says the political situation is imperfect and argues his primary task is to “reassure the population in the north”, where the Serbs live.

“We’re still needed. We provide the very essence of the backbone of the system of security,” he said, although it is not clear how long western governments will want to remain in a country that remains relatively quiet despite the absence of a lasting political solution.