Classicly

In the latter half of 1914 a few of us were writing that this war was a “War of Ideas.” A phrase, “The War to end War,” got into circulation, amidst much sceptical comment. It was a phrase powerful enough to sway many men, essentially pacifists, towards taking an active part in the war against German imperialism, but it was a phrase whose chief content was its aspiration.

People were already writing in those early days of disarmament and of the abolition of the armament industry throughout the world; they realized fully the element of industrial belligerency behind the shining armour of imperialism, and they denounced the “Krupp-Kaiser” alliance. But against such writing and such thought we had to count, in those days, great and powerful realities. Even to those who expressed these ideas there lay visibly upon them the shadow of impracticability; they were very “advanced" ideas in 1914, very Utopian. Against them was an unbroken mass of mental habit and public tradition. -- Preface by H. G. Wells.