Gods at War examines the role played by religions in starting or supporting wars from ancient Egypt and Israel to the current conflicts in Yemen and the Ukraine. It does not just cover the traditionally recognised wars of religion such as the Crusades and the Thirty Years War or the many Islamic jihads, but also addresses the role played by nearly all religions in encouraging warrior kings, dictators and even democracies to wage wars, supporting them with money, promises of a good after-life, promises of victory (God is on their side), motivating slogans and symbolism, and supportive priests to keep up morale. The account assesses the level of religious involvement in wars, including less obvious ones such as the Spanish Armada, the Ming in China, the French Revolutionary Wars, World War 1 and the Japanese War in the Pacific. For example, the prime minster of Japan who launched the attack on Pearl Harbor was a devout Buddhist and Pol Pot of the Khmer Rouge had trained as a Buddhist monk. Equally, there are examples of wars inspired by Judaism, rival Christian and Muslim sects, Sikhism and Japanese Shinto. The first section of the book discusses several different types of religious influence in conflicts, ranging from almost purely religious wars like the French or German wars of religion, to the many others where religion only played a supportive but still significant role. It also explores the reasons why religious support has been welcomed by war leaders and why religions chose to cooperate. And it draws distinctions between the documented faith of each religion and its manipulation by its leaders and priests when it suited them.

So where it is necessay to assign blame, it applies not so much to the faith but to its human management. Four main sections cover wars from the pre-Christian era, the Middle Ages, the early modern period and finally the conflicts of the 21st century including the use made of the Russian church by Vladimir Putin, of Sunni Islam by Mohammed bin Salman or of the Pentecostals in Guatemala.