"As Long As We Live, Kosovo Is Serbia"

To put it mildly, the big demonstration in Belgrade yesterday didn't go off without trouble. Crowds of angry Serbs, furious at Kosovo's declaration of independence and the support for it in western countries, attacked foreign embassies in their capital. Parts of the US embassy were set on fire, as hundreds of people went on the rampage after the rally had ended. Earlier, Serbia's Prime Minister Kostunica told the protest, "as long as we live, Kosovo is Serbia."

So things are starting to look a bit dodgy. Although one night of violence in Belgrade doesn't mean a return to the kind of wars we saw in the 1990s, the US, Britain and EU are moving quickly to tell Serbia it's got to stop. Lots of people still have guns stashed away in their lofts in the former Yugoslavia, and the situation could get out of hand frighteningly quickly.

Serbia is being emboldened by the support of Russia and China. They agree with Serbia that Kosovo's declaration of independence on Sunday broke international law. The main reason they agree is that neither wants regions of their own countries to go down the same path as Kosovo, and break away. Both Russia and China joined the UN in strongly condemning the embassy attacks, but their support for Serbia's political position means Belgrade isn't friendless as it tries to hang on to Kosovo in the face of opposition from the US and most of the EU.

The pressure from the west should ensure the violence doesn't get any worse though. Mr Kostunica may well keep up the fiery rhetoric. After all, he's got his own political future to think about, and desperately doesn't want to go down in history as the Serb PM who gave away Kosovo. But there's no sign yet of another war, and that's the thing everyone must try to avoid.