Theodore Roosevelt as I understand it, desperately wanted to help the war effort in Europe but could not get anything through Congress and The Senate. I seem to remember, ( Please correct me if I’m wrong.) one of the chief opponents to this was President Kennedy’s father. Nonetheless his sons went on to fight, suffer and die in WW2.
Roosevelt got round it with some kind of loan arrangement. A loan which the UK only finished paying off a few years ago. It was a lifeline that helped get Britain through the war. Roosevelt was able to help the UK and keep Congress etc happy.
Source:Critical Past https://youtu.be/CSptCL-Q3i4