War is at a tipping point: were passing from the age of industrial warfare to a new era of computerised warfare, and a renewed risk of great-power conflict. Humanitarian response is also evolving fast – big aid demands more and more money, while aid workers try to digitalise, preparing to meet ever-broader needs in the long, big wars and climate crisis of the future. This book draws on the founding moment of the modern Red Cross movement – the 1859 Battle of Solferino, a moment of great change in the nature of conflict – to track the big shifts already underway, and still to come, in the wars and war aid of our century. Hugo Slim first surveys the current landscape: the tech, politics, law and strategy of warfare, and the long-term transformations ahead as conflict goes digital.