The NATO intervention in Bosnia and Herzegovina in 1992 and the NATO bombing of Yugoslavia in 1999 resulted in strained relations between Serbia and NATO. Relations were further strained following Kosovo's declaration of independence in 2008 while a protectorate of the United Nations with security support from NATO. However, Serbia was invited and joined the Partnership for Peace programme during the 2006 Riga summit and in 2008, was invited to enter the intensified dialogue programme whenever the country is ready.