There is a standard.
Controversies between states and the federal government are, per article 3 of the Constitution to be submitted for resolution to the Supreme Court.
Which the rebels didn’t do, as they knew they had no case. They didn’t want resolution, they wanted war.
And they got a war. And they lost it.
Nonsense. The South did not see the situation as a “controversy” that needed to be resolved by court. They just wanted to exercise their God-given right to self rule. And they only “wanted war” in the context of, if you do allow us our right to self-rule then, bring it on.
It wasn’t that the rebels “knew they had no case”, having a “case” wasn’t and never will be germane to having the freedom to self-rule.