Concerned that the main benafits of military action were the profits made by industrialists though securing foreign sites for trade and investment, Butler suggested limiting the justification for war to self-defense and the protection of civil rights.
On retiring from the Marines,Butler voiced his concerns in a series of talks, and in war is a Racket, published in 1935 , he set out his agenda for limiting the profitability of war and restricting government's capacity to engage in offensive action overseas
Although Butler's impact at the time was limited, his views on war profiteering and US foreign policy have remained influential