Nagorno-Karabakh is a mountainous region in the South Caucasus situated roughly 100 kilometers southeast of the Armenian capital, Yerevan. Although inhabited largely by ethnic Armenians, during the Soviet period the region was an administrative division of the Azerbaijan Soviet Socialist Republic known as the Nagorno-Karabakh Autonomous Oblast (NKAO). Since 2000, three series of incidents have taken place that could be studied using high-resolution satellite imagery. To determine whether any of these clashes were accompanied by warning signs that were visible in satellite imagery, AAAS acquired multiple images of the area surrounding the reported site of each skirmish. This work formed part of a project on studying border conflict made possible by a grant from the United States Institute of Peace. Read more at www.aaas.org/geotech/borders.