When one comes to try and analyse why the League succeeded so well in its first ten years of existence, no doubt the chief reason must be found in the immense horror which the War of 1914 had created amongst the human race. Almost all those engaged in the work at Geneva had personal knowledge of the vast slaughter and destruction which the war had produced. Many had been face to face with what looked like a vivid danger of relapse into barbarism in their own countries, and there was a tremendous urge to discover some effective prevention of future wars. It was under the impulse of these feelings that we worked in those days and that we made our appeal, not in vain, for the support of the public opinion of the world.

The Future of Civilization (1938)