Is there a risk of violence?
 
Nato forces have stepped up their state of alert, especially in ethnically mixed areas of Kosovo. Commanders have promised more patrols.
 
The key question is whether they will be able to control flashpoints such as the main northern town of Mitrovica, where ethnic Serbs live north of the Ibar river and ethnic Albanians to the south.
 
The alliance was heavily criticised in 2004, when its troops failed to quell ethnic Albanian riots targeting Serbs.
 
Could violence spread?
 
The nightmare scenario would involve Kosovo Serbs who live south of the Ibar river being violently driven from their homes, and the expulsion of ethnic Albanians living in enclaves in northern Kosovo, and in the Presevo and Bujanovac regions of southern Serbia.
 
It could go further than that. There are large ethnic Albanian communities in Macedonia and Montenegro, some of whom might seek a union with Kosovo.
 
Serbia's prime minister has also suggested Belgrade could respond to a declaration of independence in Kosovo by drawing the Bosnian Serb republic (Republika Srpska) into its territory.