Final answer:
The US policy during WWII regarding lending weapons to Allied nations was the Lend-Lease program, which allowed the US to provide armaments to nations important for its defense.
Step-by-step explanation:
The US policy during WWII regarding lending weapons to Allied nations was the Lend-Lease program. This program allowed the United States to sell, lease, or transfer armaments to any nation deemed important to the defense of the United States. The program ran from 1941 to 1945 and distributed billions of dollars worth of weaponry and supplies to Britain, the Soviet Union, China, and other allies.