If you want to take a different view. Lendlease was a part of Roosevelt's plan to appear to be friendly to the British whilst pursuing his plan to break the British Empire(pretty much on its knees) and replace with it US dominated spheres of influence(in other words an American empire). 50 tired old US destroyers for 99 year leases.
To quote the Arab saying 'my enemies enemy is my friend'. It wasn't so much that Roosevelt liked the british it was just that Germany looked absolutely abhorrent and more importantly Japan, which was rampaging through China, looked like it was about to pick up all the European bases and colonies in Asia. From Indonesia all the way through to India.
Once the war was over, the speed with which the US wanted the repaying of its loans was commented on.
The US funded its allies during WWII, but unlike the British who did the same in WWI, they demanded and received repayment.