C entral Asia's impoverished and densely populated Ferghana Valley usually grabs the headlines when violence explodes in one of its cities, such as Osh in 2010 or Andijon in 2005. But some of Ferghana's most volatile hotspots are neither urban nor located on the valley floor. They are on the slopes of the surrounding mountains, where residents compete fiercely for access to the few fertile zones that dot the arid landscape. The fertile zones, which lie along rivers and streams, are the only highland areas which can support agriculture and grazing -- the economic mainstays of the region. That makes them tinderboxes for water and land disputes that can pull in not only local populations but also the governments of Tajikistan, Kyrgyzstan, and Uzbekistan, which divide the Ferghana valley among them. The outbreak of shooting on January 11 in southern Kyrgyzstan's Batken Province provides just the most recent example of how volatile the problem is. The violence concerned a 13...