Azerbaijan’s launch of reportedly intense artillery firing in the Nagorno-Karabakh region on Tuesday raised fears that another full-scale conflict with Armenia could be underway, less than three years after a war that killed more than 6,000 people. Nagorno-Karabakh, with a population of about 120,000, is an ethnic Armenian region of Azerbaijan that has been a flashpoint since the collapse of the Soviet Union. The region and sizable surrounding territories came under the control of ethnic Armenian forces backed by the Armenian military at the 1994 end of a separatist war.