Modern war conflicts, evolutionizing from large-scale collisions of armed forces to local, low-intensity, surrogate, terroristic and information wars, are associated with less direct mortality but with growing and long-lasting mental health consequences. These consequences can be traced in not only combatants and other military contingents and veterans but even to greater extent in the civilian populations, given that many modern war conflicts have signs of civil wars or religious conflicts. While active duty military undergo preliminary selection and resilience training, civilians in the war zone or as refugees and asylum-seeking victims are even at higher risk with the greater probability of transgenerational transmission, which implies long-lasting (decades) effects. Both military and civilians suffer from a similar set of disorders and psychological consequences caused by extreme trauma, including PTSD, depression, anxiety, addictions, somatization with chronic pain, dissociation, psychosocial dysfunctions, suicidal behavior, etc. War conflicts, terroristic acts, and information wars, amplified by technologically developing mass media, the internet and social networks, seem to add to a general feeling of instability and promote more anxiety, covering even wider contingents worldwide. Military psychiatry has accumulated knowledge and practical experience that, though not always can be applied directly, are useful for identification, management, prevention, and treatment of mental health consequences of war in wider contingents. This knowledge is a one more relevant and strong reason for advocating lowering of international tension and reducing the probability of war conflicts worldwide for the sake of preserving mental health of the humanity. It also has a potential of lowering the burden of this type of diseases worldwide.