So then after Pearl Harbor you think FDR should have called for peace negotiations and a cease fire? Avoid the millions of lives that were lost over the next four years?
Your comparison of the US Civil War to WWII is totally wrong and irrelevant. The situations are not similar in any way.
Something like 2,400 people killed and many billions of dollars of ships and infrastructure destroyed, and you are comparing it to the sanguine eviction of occupiers from Sumter?
You've gone round the Pearl Harbor bend. Anyone who compares the two things is not a rational person. They have no grasp of scale.