Virtually every nation, including the migratory nations, had slaves or the equivalent, at various times in their history.
That's never been a point of contention in any WBTS thread I have ever read at FreeRepublic - except as a strawman by lost causers. How many of those nations made war on itself over their insecurity regarding the institution?
The South sought to withdraw from a Federal Union. What as a practical matter did that mean? Virginia did not make war on Virginia, Virginia did not seek to make war on the Federal Government, just to withdraw from the compact. You are confusing Government with Nation, Federation with Nation, a sovereign people with a bureaucracy.
When the founding Virginians pledged along with their corresponding allies in the other former colonies--each assuming national sovereignty--their lives, their fortunes & their sacred honor, in a solemn undertaking; they surely had a right to expect mutual respect. When more & more of the posterity of their former allies & compatriots, instead turned to insult; many considered the moral bond from the great joint venture to be dissolved.
If you formed a partnership with a group of others; if you pledged your lives, fortunes & sacred honor to a joint venture, and found yourself no longer respected by some of those joint-venturers, involved; would you feel you were the one betraying the compact, if you elected to disassociate from that venture? Well maybe you would, but most of us would not.
We are not talking about insecurity, but insult; not talking about a particular institution, so much as violation of a sacred promise to respect each the others' institutions, whatever they were. (The Constitution has many provisions that reflect that understanding--i.e., mutual respect, as an essential.)