World War I casualties
Casualty statistics for World War I vary to a great extent; estimates of total deaths range from 9 million to over 15 million. Military casualties reported in official sources list deaths due to all causes, including an estimated 7 to 8 million combat related deaths (killed or died of wounds) and another two to three million military deaths caused by accidents, disease and deaths while prisoners of war. Official government reports listing casualty statistics were published by the United States and Great Britain. These secondary sources published during the 1920s, are the source of the statistics in reference works listing casualties in World War I. This article summarizes the casualty statistics published in the official government reports of the United States and Great Britain as well as France, Italy, Belgium, Germany, Austria and Russia. More recently the research of the Commonwealth War Graves Commission (CWGC) has revised the military casualty statistics of the UK and its allies; they include in their listing of military war dead personnel outside of combat theaters and civilians recruited from Africa, the Middle East and China who provided logistical and service support in combat theaters. The casualties of these support personnel recruited outside of Europe were previously not included with British war dead, however the casualties of the Labour Corps recruited from the British Isles were included in the rolls of British war dead published in 1921. The methodology used by each nation to record and classify casualties was not uniform, a general caveat regarding casualty figures is that they cannot be considered comparable in all cases.
World War II
World War II (often abbreviated to WWII or WW2), also known as the Second World War, was a global war that lasted from 1939 to 1945. The vast majority of the world's countries—including all the great powers—eventually formed two opposing military alliances: the Allies and the Axis. A state of total war emerged, directly involving more than 100 million people from over 30 countries. The major participants threw their entire economic, industrial, and scientific capabilities behind the war effort, blurring the distinction between civilian and military resources. World War II was the deadliest conflict in human history, marked by 50 to 85 million fatalities, most of whom were civilians in the Soviet Union and China. It included massacres, the genocide of the Holocaust, strategic bombing, premeditated death from starvation and disease, and the only use of nuclear weapons in war.