Yeah, sure. The ring of forts and thousands of troops around the national capital were put there for no reason at all.
Okay, I see your problem. You are a time traveler and you can't keep your historical events in the proper order. You've got this happening before that, and this subsequent thing in front of that other triggering event.
Your sequence is all out of whack.
At the time the Union invaded, the South was not posing any threat to them. The South was not going to invade. Later? Yeah, it's sort of what you have to do when you go on an offensive in a f***ing WAR.
Well, other than the fact that they were in rebellion against the duly constituted government, and were trying to rip away nearly half of the republic's territory, and had raised a substantial army to attack the legitimate government.
The South was not going to invade. Later? Yeah, it's sort of what you have to do when you go on an offensive in a f***ing WAR.
It's what you do when you're an insurrectionist who is losing the insurrection and you're getting desperate, so desperate that you're willing to throw all the chips on the table for a final roll of the dice.