In the new book of the famous military historian B.V. Sokolov, using original scientific methods, the human losses of Russia and the USSR in the wars of the 20th - 21st centuries are determined. - from the Ihetuen (Boxer) uprising and the Russian-Chinese conflict, right up to the civil war in Syria. The book focuses on losses in the First and Second World Wars. The losses of Russia and Germany and the First World War and the USSR and Germany in World War II are especially studied in detail.