The signs this weekend suggest that the immediate crisis over Kosovo has been defused. Some Serbian troops are pulling back from the border, and the threat of a return to armed conflict has receded for now. The Biden administration acted decisively on Friday, drawing on some of the lessons from the run-up to the Ukraine invasion, going public with US intelligence on Serbian troops movements, and calling Belgrade to threaten sanctions and ostracism. The Nato peacekeeping force, Kfor, was immediately reinforced by the transfer of command of a battalion of British troops who were in the region for training. While the immediate danger may have passed however, the chronic crisis over Kosovo continues to fester. Fifteen years after the former Serbian province declared independence, Kosovo is still in limbo on the world stage, with recognition from just over half the UN’s 193 member states. In the late 1990s, Serbia fought to stop it breaking away after years of oppression of its ethnic Albanian population. Belgrade’s brutal counter-insurgency and campaign of ethnic cleansing triggered a Nato intervention and aerial bombing campaign in 1999 that ultimately led to Serbian withdrawal. Kosovo’s formal independence only came nine years later after UN-sponsored consultations and a plan designed to give substantial protections to the new country’s Serb minority. Since then Serbia and its principal backer, Russia, have fought a rearguard campaign to block Kosovo’s membership of international bodies, boosted by fears of many states, including five EU members, that recognition will set a precedent for their own ethnic minorities to secede. Belgrade has also kept the situation in four northern majority-Serb municipalities in a constant state of foment, sometimes helped by heavy-handed efforts to demonstrate sovereignty by the government in Pristina. Kosovo still cannot take its own existence for granted. The events of the past week could be an inflection point, depending on whether they lead to a policy rethink in Washington and Brussels. Both have been heavily invested in a Franco-German plan for normalising relations, in which Serbia would not have to grant full recognition but at least recognise Kosovo’s passports, flag and other attributes of nationhood, Belgrade would stop blocking Kosovo from membership of multilateral institutions, and in return Pristina would allow an association of Serb-majority municipalities, solidifying their autonomy. Serbia’s president, Aleksandar Vučić, and the Kosovan prime minister, Albin Kurti, agreed to these principles in EU-brokered meetings, but Vučić refused to sign any document, and reassured his own public he would never allow Kosovo to become a UN member. Kurti consequently refused to go ahead with the association of Serb municipalities, refusing to trust assurances from EU mediators that Serbia would fulfil its own promises at a later date. The response from Washington and Brussels was to put exclusive blame on Kurti, largely because Vučić has been able to play off western governments against Russia and China in competition for Belgrade’s favour. The US for example was grateful for Serbian votes against Russia in UN general assembly debates on Ukraine, despite Belgrade’s staunch opposition to sanctions on Moscow. The Biden administration and the EU must now examine whether they have been taken for a ride. While Vučić said all the right things in private, the government was building up the Serbian military, and flooding the country’s media with hate and fear of Kosovo, falsely accusing Kurti of carrying out “brutal ethnic cleansing”. On 24 September a paramilitary group of well-armed Kosovo Serbs ambushed a Kosovan police patrol, and in the fight that followed, one police officer and three Serb gunmen were killed. The Kosovan government presented evidence to show that the group had been armed and controlled from Belgrade, and US officials have privately made clear they find that evidence compelling. The ambush could have been designed to ignite a conflict in northern Kosovo that would give cover for Belgrade to send in troops ostensibly to protect ethnic Serbs. An alternative aim could have been to force Kfor to bolster its presence and take back primary responsibility for security in northern Kosovo from Pristina. That would be a step backwards for the country’s sovereignty. If the latter was the case, Vučić has already partly succeeded. Whether he wins entirely depends now on the direction of western policy.