After his retirement from the Marine Corps, Butler made a nationwide tour in the early 1930s giving his speech "War is a Racket". The speech was so well received that he wrote a longer version as a small book with the same title that was published in 1935 by Round Table Press, Inc., of New York. The booklet was also condensed in Reader's Digest as a book supplement which helped popularize his message. In an introduction to the Reader's Digest version, Lowell Thomas, the "as told to" author of Butler's oral autobiographical adventures, praised Butler's "moral as well as physical courage".
"War is a racket. It always has been. It is possibly the oldest, easily the most profitable, surely the most vicious. It is the only one international in scope. It is the only one in which the profits are reckoned in dollars and the losses in lives. A racket is best described, I believe, as something that is not what it seems to the majority of the people. Only a small 'inside' group knows what it is about. It is conducted for the benefit of the very few, at the expense of the very many. Out of war a few people make huge fortunes."
The book has significance historically as Butler points out in 1935 that the US is engaging in military war games in the Pacific that are bound to provoke the Japanese.
"The Japanese, a proud people, of course will be pleased beyond expression to see the United States fleet so close to Nippon's shores. Even as pleased as would be the residents of California were they to dimly discern through the morning mist, the Japanese fleet playing at war games off Los Angeles."
Butler explains that the common rationale for the buildup of the US fleet and the war games is fear that "the great fleet of this supposed enemy will strike suddenly and annihilate 125,000,000 people."
In his penultimate chapter, Butler argues that three steps are necessary to disrupt the war racket:
Making war unprofitable. Butler suggests that the owners of capital should be "conscripted" before other citizens are: "It can be smashed effectively only by taking the profit out of war. The only way to smash this racket is to conscript capital and industry and labour before the nation's manhood can be conscripted. … Let the officers and the directors and the high-powered executives of our armament factories and our steel companies and our munitions makers and our ship-builders and our airplane builders and the manufacturers of all other things that provide profit in war time as well as the bankers and the speculators, be conscripted — to get $30 a month, the same wage as the lads in the trenches get."
Acts of war to be decided by those who fight it. He also suggests a limited referendum to determine if the war is to be fought. Eligible to vote would be those who risk death on the front lines.
Limitation of militaries to self-defense. For the United States, Butler recommends that the navy be limited, by law, to within 200 miles of the coastline, and the army restricted to the territorial limits of the country, ensuring that war, if fought, can never be one of aggression.