The plan mentioned was probably one of the Rainbow plans. Rainbow 5.
"When
Franklin D. Roosevelt was reelected in 1940, the chief of naval operations submitted a paper to the president. Known as Plan Dog, it recommended secret staff talks with the British and a Germany‐first strategy in case of a two‐ocean war. Early in 1941, American and British staff officers met secretly in Washington. The ABC‐1 Conference accepted the Germany‐first approach and agreed to create a permanent structure for Allied decision making. In November 1941, the Americans revised Rainbow‐5 into a two‐ocean war plan with a Germany‐first strategy and a defensive strategy in the Pacific until the fate of Germany was sealed.
The Joint Board also wrote an estimate of requirements for a global war. The army's Victory Program, prepared by September 1941, called for massive forces (a wartime army and air force of 8.7 million men) that would ensure complete destruction of the Axis powers and avoid the perceived mistakes of 1918. For the first time in the nation's history, the United States had established a grand strategy and had agreed to participate in a coalition prior to the outbreak of hostilities."
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