The Soviet Union became a multi-party semi-presidential republic from March 1990 until its dissolution in December 1991, resulting in eleven new countries (Armenia, Azerbaijan, Belarus, Georgia, Kazakhstan, Kyrgyzstan, Moldova, Tajikistan, Turkmenistan, Ukraine, and Uzbekistan), which had declared their independence from the Soviet Union in the course of the year, while the Baltic states (Estonia, Latvia and Lithuania) regained their independence in September 1991 following the Singing Revolution. The rest of the Soviet Union, which constituted the bulk of the area, continued with the establishment of the Russian Federation in December 1991. Albania and Yugoslavia abandoned communism between 1990 and 1992. By 1992, Yugoslavia had split into five new countries, namely Bosnia and Herzegovina, Croatia, Republic of Macedonia, Slovenia, and the Federal Republic of Yugoslavia, which was later renamed Serbia and Montenegro in 2003 and eventually split in 2006 into two states, Serbia and Montenegro. Serbia was then further split with the breakaway of the partially recognized state of Kosovo in 2008. Czechoslovakia dissolved three years after the end of Communist rule, splitting peacefully into the Czech Republic and Slovakia on 1 January 1993. The impact of these events was felt in many socialist states. Marxism–Leninism was abandoned in countries such as Ethiopia (1991), South Yemen (1990, unified with North Yemen), Angola (1991), Benin (1990), Congo-Brazzaville (1991), Mozambique (1990), Somalia (1991), Afghanistan (1992), Angola (1992), Mongolia (1992), and Cambodia (1993).