Final answer:
President Franklin Roosevelt promoted the Lend-Lease Act to provide material support to Britain and other countries fighting the Axis powers, under a program that lent or leased military supplies for future repayment or leasing rights, which helped sustain the U.S. defense without directly entering WWII.
Step-by-step explanation:
President Franklin Roosevelt encouraged the passage of the Lend-Lease Act to support allies like Britain without the United States directly entering World War II. The Act, passed in March 1941, allowed the U.S. to lend or lease military supplies in exchange for future repayment or for lease rights at allied bases. This program aimed to bolster the defense capabilities of countries vital to U.S. security, by enabling them to continue their fight against Axis powers, particularly Nazi Germany.
Roosevelt's initiative was informed by the situation in Britain, fighting alone against the Nazis and with diminishing gold reserves making the previous cash-and-carry policy untenable. The Lend-Lease Act represented a pragmatic approach to promote U.S. defense interests by aiding those engaged in the conflict while respecting the prevalent isolationist sentiment among American citizens.