It's been a good day for Kosovo. That's the little part of south-east Europe that used to be part of Yugoslavia and then Serbia, and was latterly run by the UN after the 1999 war waged by NATO to end Slobodan Milosevic's attempts at ethnic cleansing. Kosovo finally declared independence from Serbia in February, and since then nearly 50 other countries have recognised that independence. Today, two of the other bits of the old Yugoslavia, Montenegro and Macedonia, also did.
Serbia went through the motions of being angry about it, and expelling Montenegro's ambassador to Belgrade. The Serbian government has to do that, because there's still plenty of its citizens who believe Kosovo should always remain part of Serbia. That feeling's been central to the idea of Serb nationalism for more than six centuries, even though these days most of the people who live there are ethnic Albanians (the same Albanians Milosevic wanted to kick out back in 1999).
But even though Serbia also this week won a vote at the UN allowing it to challenge Kosovo's independence at the International Court of Justice, it's got no realistic chance of hanging on to its former province. It's already allowed back the ambassadors of western European countries which recognised Kosovo earlier in the year. The leaders in Belgrade know that if they want to continue to move their country closer to the rest of the world, and crucially the EU, they can't play games over Kosovo. When Serbia expresses disgust at the latest developments, it's really just keeping up appearances.