Since 2001, more than 2 million U.S. military personnel have deployed in to Iraq and Afghanistan. Recent estimates suggest that between 17-20 of Soldiers returning from these conflicts meet criteria for posttraumatic stress disorder PTSD upon their return. Notably, sleep disturbance is one of the primary complaints of combat-related PTSD patients. Recent evidence suggests that sleep may play a critical role in the ability to effectively extinguish conditioned fear responses and is necessary for consolidating positively valenced emotional memories. Furthermore, many PTSD patients do not respond to currently available treatments, and sleep disturbance is a frequent residual symptom even among those patients who do respond. Thus, sleep disturbance, as a symptom of PTSD, may lead to a vicious circle that prevents full resolution of the conditioned fear responses, sustaining continuation of the disorder.