Nagorno-Karabakh
During the 20th century, Nagorno-Karabakh had been denied an Armenian identity by the succeeding Russian, British, and Azeri rulers.
The Armenians of Nagorno-Karabakh had accused the Soviet Azerbaijani government of conducting forced ethnic cleansing of the region. The majority Armenian population, with ideological and material support from Armenia, started a movement to transfer the territory to Armenia. The issue was at first a "war of words" in 1987. In a December 1991 referendum, the people of Nagorno-Karabakh approved the creation of an independent state. A Soviet proposal for enhanced autonomy for Nagorno-Karabakh within Azerbaijan satisfied neither side. After the dissolution of the Soviet Union in 1991, a land war erupted between the Armenians and Azerbaijan over the disputed area.
In the post-Soviet power vacuum, military action between Azerbaijan and Armenia was heavily influenced by the Russian military. Furthermore, the Azeri military employed a large number of mercenaries from Ukraine and from Russia. As many as one thousand Afghan mujaheddin participated in the fighting. There were also fighters from Chechnya fighting on the side of Azerbaijan.
By the end of 1993, the conflict had caused thousands of casualties and created hundreds of thousands of refugees on both sides. By May 1994 the Armenians were in control of 14% of the territory of Azerbaijan. As a result, the Azerbaijanis started direct negotiations with the Karabakhi authorities. An unofficial cease-fire was reached on May 12, 1994 through Russian negotiation. But, a final resolution to the conflict has yet to be realized.
Read more about this topic: Military History Of Armenia