The Republic of Kosovo’s assembly declared independence (for the second time) in February 2008 – an action still disputed by many countries, including Serbia, which previously claimed sovereignty over Kosovo. According to the CIA World Factbook, more than 60 countries, including the US, have recognized the fledgling state, and it has since joined the International Monetary Fund and World Bank.
Predominantly Albanian, Kosovo is located in southeastern Europe and was formerly part of the Republic of Yugoslavia as well as a semiautonomous province of Serbia. It has clamored for independence for many years, and first declared it in 1991 via a self-organized referendum. That declaration did not stick and international mediation efforts continued for a couple of years before the Kosovar assembly took matters into its own hands and declared independence.
Serbia requested in 2008 that the International Court of Justice, whose opinions are nonbinding, weigh in on whether Kosovo could declare independence from Serbia. The court decided that while the declaration of independence was not exactly illegal, it wasn’t official. Regardless, the actions of the international community, including the US, seem to imply the independence is valid.