Whether the South would have collapsed without slavery is not the issue-the South BELIEVED it would at the time and thus acted in their best interest at the time.
I respectfully disagree. Arkansas seceded due to Lincoln's demand for troops. It had nothing to with a belief that the South would collapse in the absence of slavery. Arkansas rejected the notion that the Federal government had the authority to use force to coerce the seceded states back into the Union.
Virginia, North Carolina, Tennessee and Arkansas all seceded after the Confederacy declared war on the United States, May 6, 1861.
They wanted war. They chose war. They got war.
They should be happy.