In a December 1991 referendum, that was taking place along with similar referendums all around the USSR, and boycotted by most of the local Azerbaijanis, the yet majority population of Armenians in Nagorno-Karabakh approved the creation of an independent state. However, the Constitution of the USSR was the instrument in accordance to which only the 15 Soviet Republics could vote for independence and Nagorno-Karabakh was not one of the Soviet Republics. A Soviet proposal for enhanced autonomy for Nagorno-Karabakh within Azerbaijan satisfied neither side and subsequently led to the eruption of war between Armenia-backed Nagorno-Karabakh and Azerbaijan.