This is a first rate history of the year Europe fell into an abyss that it has still yet to recover from. Hastings, a gifted writer, takes us from the politico-military decision making that sets stage for the Great War. He is definitely in the Fischer school which pins most of the blame for the war on Germany and as a result, he downplays the roles of France and Russia in starting the war. For a more nuanced view I would recommend Chistopher Clark's "Sleepwalkers....." From there he goes on to the battles of the early months of the war. He not only focuses on the western front, but he is very detailed with respect to the eastern front from carnage in Serbia to the German victory at Tannenberg. He is at his best when he discusses the failure of the generals on both sides, whose blunders amplfy the carnage.
Where I disagree with Hastings is his assertion that that Britain's intervention which saved France at the Battle of the Marne in September 1914 was worth all of the carnage that was to come. He views that had Germany won a quick victory 1914 Europe would have been enslaved under the boot of German authoritarianism. This is a tough swallow for me. Although there are no proofs in counter-factual history, I could just as easily visualize a post Wilhelmine Germany evolving into a version of what it is today.