It was equally dishonorable for the north to invade the south when the south exercised their right to leave the union.
But George Washington said that there should be an "immovable attachment" to the national union.
Are you faulting the men who took that idea to heart?
"I do not conceive we can exist long as a nation, without having lodged somewhere a power which will pervade the whole Union in as energetic a manner, as the authority of the different state governments extends over the several states. To be fearful of vesting Congress, constituted as that body is, with ample authorities for national purposes, appears to me to be the very climax of popular absurdity and madness."
George Washington to John Jay, 15 August 1786
More Washington:
"In all our deliberations on this subject we kept steadily in our view, that which appears to us the greatest interest of every true American, the consolidation of our Union, in which is involved our prosperity, felicity, safety, perhaps our national existance. This important consideration, seriously and deeply impressed on our minds [at the constitutional convention] led each State in the convention to be less rigid on points of inferior magnitude...the constitution, which we now present, is the result of of a spirit of amity, and of that mutual deference and concession which the peculularity of our political situation rendered indispensible."
George Washington to the Continental Congress September 17, 1787
To abandon the national union, you have to abandon the words of George Washington.
The loyal Union men were not ready to do that.
Walt
The british government said the same thing. IN the course of human events it sometimes becomes necessary to part ways. The war between the states was one of them. No union is permanent, they only last while they have the consent of the whole people. A large percentage (roughly half?) of the people of those Untied States chose to no longer be untited.
According to your thought process (apparently) we should all still be british citizens.