Long before Pearl Harbor, the League opposed the principle of the Neutrality Acts—that the U.S. should treat all belligerents the same. Although not all members agreed, and some resigned in protest, the League supported Lend-Lease. It supported price controls, rationing, higher taxes and especially a new world system of collective security.

When the Dumbarton Oaks proposal for the United Nations was presented, the League began an intensive campaign in support.  Also strongly supported were the push for civilian control of atomic energy, the European Recovery Program and the concept of world trade.