Warfare is at a tipping point today as it passes from the age of industrial warfare to a new era of computerized warfare and a renewed risk of "big war" between global powers. Humanitarian response is also developing fast as "big aid" demands more and more money and tries to digitalize and prepare for new needs in long wars and escalating climate crisis. This book starts with the founding moment of modern of the Red Cross and Red Crescent movement at the Battle of Solferino in 1859 and tracks the big changes in war and humanitarian response in our own times. Organized in three parts, it assesses twenty first century experience of warfare, civilians and humanitarians and looks at where they are heading in the next ten years. It examines the nature of warfare in the century so far and how it is now being transformed by digitalization. It explains how civilians suffer and survive in wars today and how "digital civilians" will be central in wars to come. Finally, it looks at today's big humanitarian agencies and how their world is changing too. Inspired by Henri Dunant's seminal humanitarian text, completed 160 years ago in 1862, Hugo Slim alerts military and humanitarian policymakers alike to the big changes underway in their professions and points to key areas where they must adapt or fail.