Harrowing war photographs show a Japanese soldier preparing to behead a Chinese soldier in the late 1930s in Nanking, China

The book focuses on the behaviour of five groups in history including the Japanese Army in China in 1937 - the start of the second Sino-Japenese war between China and the Empire of Japan which came to an end, along with the Second World War, in 1945.

In just six weeks, hundreds of thousands of Chinese soldiers and civilians were slaughtered by the Imperial Army in and around Nanking, which was then the capital of China.

Another group examined by Zapotoczny is the Einsatzgruppen - paramilitary death squads of Nazi Germany that were responsible for mass killings, primarily by shooting. 

Nazi behaviour in Russia during the war is also analysed along with the actions of the Red Army after it had swept into Berlin in 1945.

Zapotoczny also examines pictures from the My Lai massacre - one of the most notorious incidents of the Vietnam War. Up to 500 unarmed civilians were killed by U.S. soldiers during the episode in South Vietnam on March 16, 1968.

Harrowing war photographs show a Japanese soldier preparing to behead a Chinese soldier in the late 1930s in Nanking, China

Separate photos show Russian soldiers appearing to harass women in Berlin in 1945 after the Red Army had swept into the German city

Most of the women were children or elderly, and some of the bodies were later found to be mutilated. Details only came to light publicly in 1969, prompting widespread outrage and fueling opposition to the war. 

The book also focuses on the American guards who tortured inmates at Abu Ghraib in 2004. Photos depicting abuse at the Iraq jail began to emerge in 2004, with some detainees claiming to have endured physical and sexual abuse, electric shocks and mock executions

Zapotoczny's book shows horrifying pictures of Chinese women who were raped by Japanese soldiers in Nanking. Others show a Japanese guard preparing to cut off a Chinese soldier's head and bayoneting Chinese people in a pit.

Separate photos show Russian soldiers appearing to harass women in Berlin in 1945 and Vietnamese women and children huddled together before being killed at My Lai.

'The history of warfare is filled with accounts of brutality. The behaviour of any human being is, of course, a very complex phenomenon whether in war or in peace,' said Zapotoczny in the book's preface.

Nazi soldiers carry out a mass execution of Polish hostages in retaliation for an attack on a police station by Poland's underground resistance