Azerbaijan - a nation with a majority-Turkic and majority-Shia Muslim population - was briefly independent (from 1918 to 1920) following the collapse of the Russian Empire; it was subsequently incorporated into the Soviet Union for seven decades. Azerbaijan has yet to resolve its conflict with Armenia over Nagorno-Karabakh, a primarily Armenian-populated region that Moscow recognized in 1923 as an autonomous republic within Soviet Azerbaijan after Armenia and Azerbaijan disputed the territory's status. Armenia and Azerbaijan began fighting over the area in 1988; the struggle escalated after both countries attained independence from the Soviet Union in 1991. By May 1994, when a cease-fire took hold, ethnic Armenian forces held not only Nagorno-Karabakh but also seven surrounding provinces in the territory of Azerbaijan. The OSCE Minsk Group, co-chaired by the United States, France, and Russia, is the framework established to mediate a peaceful resolution of the conflict. Corruption in the country is widespread, and the government, which eliminated presidential term limits in a 2009 referendum, has been accused of authoritarianism. Although the poverty rate has been reduced and infrastructure investment has increased substantially in recent years due to revenue from oil and gas production, reforms have not adequately addressed weaknesses in most government institutions, particularly in the education and health sectors.