Abstract
During the second half of the20th century, the development of oil economies in North Africa and repeated drought in the Sahel transformed Saharan and trans-Saharan patterns of exchange and mobility, introducing a steep north-south gradient. With demographic growth, rapid urbanization, and gradual replacement of caravans by trucks, licit and illicit trade and migration intensified and diversified. As, more recently, the Sahara has moved center-stage in a number of strategic domains - mineral resource extraction, migration control, counter-terrorism, and environmental crisis management - Saharan economies everywhere have been affected by national and international security interventions, compounding, in many cases, ongoing internal conflict and war.
