Military psychiatry is a specialized field focused on the mental health of military personnel and their families, aiming to keep individuals fit for duty and treat conditions ranging from routine life stresses to combat-related trauma. These psychiatrists provide counseling, substance abuse prevention and treatment, and medical care for various mental illnesses. Notably, Arne Sund, from the 1960s, established Norwegian military psychiatry as a leader within NATO and founded the research field of disaster psychiatry. In the United States, active duty members and their families access mental health services through TRICARE, while veterans receive comprehensive care, including for PTSD, depression, and substance use, via the Department of Veteran Affairs (VA) and its 24/7 crisis line. Historically, psychiatric disorders have led to a significant number of military casualties and discharges, underscoring the critical role of on-site emergency psychiatric treatment in reducing morbidity.