FDR wanted the US to join the Allied powers because of his sympathies to the British however before the attacks on Pearl Harbor when polled on going to war only 7-14 percent of Americans favored going to war. We now he had these sympathies because of his communications with Prime Minister Winston Churchill because they had created a friendship so FDR knew the situation the British were in so he lobbied congress to allow the US to at least do Lend Lease and also getting rid of bans in about the selling of arms to powers at war.
Moral diplomacy is a form of diplomacy proposed by US President Woodrow Wilson in his 1912 election. Moral diplomacy is the system in which support is given only to countries whose moral beliefs are analogous to that of the nation.