Throughout history atrocities carried out by armed forces against non-combatant civilians have been so frequent that they could easily be regarded as the norm rather than the exception. Today such atrocities are held to be ‘war crimes’ or ‘crimes against humanity’. War crimes are serious violations of international law during times of war and include torture and murder of prisoners of war and civilians and forcing them to work as slave labour. ‘Crimes against humanity’ are war crimes on a large scale; systematic atrocities (i.e. not isolated crimes by individual soldiers and units) which are either the policy of a government or are condoned or tolerated by that government. But these atrocities have not always been seen as criminal acts.
The term ‘war crimes’ came into use during World War I. Abraham Lincoln described slavery as a “crime against humanity” and the Allied powers in World War I used the term to describe the mass killing of Armenians by the Ottoman Empire in 1915. But it is only after 1945, and as a result of the Holocaust and the long list of atrocities by the Third Reich against civilians in Germany and in the occupied countries, that political and military leaders were brought to trial and specifically charged with crimes against humanity.
In 1945 the victorious Allied Powers established International Military Tribunals in the German city of Nuremberg and in Tokyo to prosecute political and military leaders and some individual soldiers for crimes against peace, violations of peace treaties, war crimes and crimes against humanity. Some military officers were also tried in the countries where they had perpetrated war crimes.