What, not "Marxist dialectic" verbiage in this one? The assertion that Pearl Harbor has any resemblance to Ft. Sumter is your "Jumped the Shark" demonstrator.
Even Seward admitted that Ft. Sumter was worthless to the Union. What is it now? A Park?
Sorry, but you'll have to find somebody other than Seward to defend your "Sumter didn't count" argument.
In fact, like everyone else, north and south, Seward understood that the Confederate assault on Fort Sumter was the beginning of Civil War.
Just as the Japanese assault on Pearl Harbor was the beginning of WWII for Americans.
Relatively speaking, the US Army force in Fort Sumter in early 1861 was roughly the same size, compared to the total US Army, as US forces in Hawaii in 1941, compared to the then total military.
Yes, casualties at Fort Sumter were relatively fewer, but on the other hand: the US kept Pearl Harbor after the attack, so the loss of Sumter was relatively more important.