Today's network-centric battlefield environment is highly stressful and cognitively demanding. Many warfighters are feeling overwhelmed and end up being medically evacuated from theater due to mental health problems [i.e., post traumatic stress disorder (PTSD) and depression]. Of a sample of troops evacuated for psychiatric reasons, 21% (106 out of 509) had psychiatric histories prior to deploying to the theater of operations. Most cases were either related to stress (i.e., PTSD, n - 33, 310%) or to depression (n = 72, 66%). Stress disorders and depression predominate among the psychiatric causes for medical evacuation. This review paper discusses stress theories as they pertain to warfighting, the types of stress and stress disorders most prevalent on modern battlefields, the relationships among stress, psychiatric disease, and cognitive performance, and potential methods to decrease some types of stress-related acute and chronic disorders (i.e., virtual-reality stress inoculation training).