The tension in Yerevan was palpable. Overnight April 1, just a few days before I arrived in the city, fighting had broken out in the disputed territory of Nagorno-Karabakh, home to a quasi-independent statelet backed by Armenia known as the Nagorno-Karabakh Republic. The line of contact where Karabakh fighters clashed with Azerbaijani soldiers was around 300 kilometers (186 miles) away, but in Yerevan it felt much closer. I found myself in the city amid the breakdown of a cease-fire that had largely held since 1994....