Hashim Thaçi in the context of "Rambouillet Agreement"

The 2008 Kosovo declaration of independence, which proclaimed the Republic of Kosovo to be an independent and sovereign state, was adopted at a meeting held on 17 February 2008 by 109 out of the 120 members of the Assembly of Kosovo, including the Prime Minister of Kosovo, Hashim Thaçi, and by the President of Kosovo, Fatmir Sejdiu (who was not a member of the Assembly). It was the second declaration of independence by Kosovo's Albanian-majority political institutions; the first was proclaimed on 7 September 1990.

The legality of the declaration has been disputed. Serbia sought international validation and support for its stance that the declaration was illegal, and in October 2008 requested an advisory opinion from the International Court of Justice. The Court determined that the declaration did not violate international law.

The First Agreement of Principles Governing the Normalisation of Relations, informally known as the Brussels Agreement (Serbian: Бриселски споразум / Briselski sporazum, Albanian: Marrëveshja e Brukselit), is an agreement to normalize relations between the governments of Serbia and Kosovo. The agreement, negotiated and concluded in Brussels under the auspices of the European Union, was signed on 19 April 2013. Negotiations were led by Serbian prime minister Ivica Dačić and Kosovo prime minister Hashim Thaçi, mediated by EU High Representative Catherine Ashton. The government of Serbia does not recognize Kosovo as a sovereign state, but began normalising relations with the government of Kosovo as a result of the agreement. In Belgrade, the agreement was criticized by protestors as a convalidation of Kosovo independence.

On 17 February 2008, the majority of members of the Assembly of Kosovo, including Hashim Thaçi, and Fatmir Sejdiu (who were not members of the Assembly), not acting in the capacity of PISG, declared Kosovo an independent and sovereign state. Kosovo was soon recognized as a sovereign state by the United States, Turkey, Albania, Austria, Germany, Italy, France, the United Kingdom, the Republic of China (Taiwan), and others. This triggered an international debate over whether Kosovo's unilateral declaration of independence had set a precedent in international law that could apply to other separatist movements, or whether it is a special case. The recognition of Kosovo's independence by 101 out of 193 UN states, according to many sources, has given fresh impetus to other separatist movements.

It is estimated that a total of 70 unrecognized nations and organizations use the Kosovo precedent to achieve their goals. Abkhazia and South Ossetia renewed their calls for the recognition of their sovereignty. Kosovo's independence also led to increased tensions in Bosnia and Herzegovina, where the Republika Srpska vetoed recognising Kosovo, and threatened to declare independence themselves.