Clark takes a primarily unbiased approach in describing the events and actors that led Europe into the First World War. Towards the end, you can't help but feel that Russia and France have not been given enough attention in WWI historiography for the role each played in 1914 and before. Sleepwalkers is a long book, but provides all the information you need to understand comparatively how the war broke out -- starting with the regicide of the Obrenović monarchy in Serbia and going through the July Crisis.