This, from Hemingway’s introduction to the 1948 illustrated edition of A Farewell to Arms:
The title of the book is A Farewell to Arms and except for three years there has been war of some kind almost ever since it has been written. Some people used to say, why is the man so obsessed with war, and now, since 1933 perhaps it is clear why a writer should be interested in the constant, bullying, murderous, slovenly crime of war. Having been to too many of them, I am sure that I am prejudiced, and I hope that I am very prejudiced. But it is the considered belief of the writer of this book that wars are fought by the finest people that there are, or just say people, although, the closer you are to where they are fighting, the finer people you meet; but they are made, provoked and initiated by straight economic rivalries and by swine that stand to profit from them. I believe that all the people who stand to profit by a war and who help provoke it should be shot on the first day it starts by accredited representatives of the loyal citizens of their country who will fight it.