I doubt that.
Roosevelt's focus from the beginning was Nazi Germany, so he was not going to be sidetracked into the Pacific while leaving leaving the main problem unattended to.
Today no one knows how FDR might have finessed it, but everything I've read implies that he would sooner, not later, have refocused the US efforts towards Germany, regardless of whether Hitler declared war, or not.
Once the US was in it, we were in it to win it, and Hitler's Germany faced total destruction.
I doubt that.
Roosevelt’s focus from the beginning was Nazi Germany, so he was not going to be sidetracked into the Pacific while leaving leaving the main problem unattended to................................................... We were divided, many did not want to be involved in another war in Europe. Dec. 8 1941, the lines at the recruiting office were for Japan. Remember Roosevelt said; “I hate war, Elenore hates war and even Faller hates war”, he also said no American Boy would set foot on foreign soil. Sure he was out to save Churchill, no big secret there. Joseph Kennedy our ambassador to England, advised against going to war against Germany. There was also congressional opposition to the war. Hitler declaration of war made it easy for Roosevelt, and Churchill was ecstatic. Hitler was hoping that Japan would help him with Russia. Tsk Tsk, it was the biggest blunder he made, it probably cost him the war.