A central interest of Ferro's is the various socialist movements: their failure to stop the war, their response to the war, their incorporation into war governments, and their role in ending it. He devotes a full four pages to the text of the Zimmerwald Manifesto, produced by a secret meeting of socialists in Switzerland in September 1915. Other focuses include social history generally, while Ferro's perspective is clearly French.
Part I covers the background to the war. Ferro touches on social unrest, forms of patriotism and nationalism, imperialism and alliances, the inevitability of war, and plans for and speculations about it. He devotes a chapter to the socialist International and its failure to mobilise anti-war sentiment. And in eight pages he describes the immediate lead up to war, from the assassination of Franz Ferdinand.
Part II covers the course of the war, roughly chronologically but with shifting thematic focuses. The early war of movement, the halting of the German attack on the Marne, and the stagnation of the front. The search for weak points, in the German offensive against Russia, the attack on Serbia, and the Allied campaigns in the Middle East, the Balkans, and Gallipoli. The great battles of Verdun, the Somme and Passchendaele, the experience of battle, and innovations in military technology. Diplomatic campaigns, the blockade and submarine warfare. The spread of total war, in the involvement of the United States, economic mobilization, and propaganda. Finance and trade — the opposing sides traded with one another indirectly, sometimes even in munitions — and internal disagreements within the Allied powers and the Central Powers.
Part III focuses on the political and social ramifications of the war. It created new tensions and exposed old ones: between parliaments and executive governments, between soldiers and civilians, and within the working class and socialist movements. Internal crises ranged from changes in government and mutinies in France to the fall of the Tsar in Russia. Attempts to hold a socialist peace conference in Stockholm fell through and anti-war socialists went their own way in Russia, lacked power in Germany despite the socialist Reichstag majority, and were repressed in France and Italy.
One chapter in Part IV covers the Bolshevik Revolution and its broader effects. A somewhat abrupt final chapter describes the failure of Ludendorff's final offensives, the Allied counterattacks and their victories in the East, and almost as an afterthought the actual armistice; it briefly looks at the social and economic consequences of the war.
The Great War is not recommended as an introduction to World War I for newcomers, given its idiosyncratic choice of material, but it offers a perspective that may be new to many. And it's an easy and enjoyable read.