The news from Aleppo makes me wonder how different our own history might have been if Lincoln had just said to the six deep south states that had seceded by the end of January 1961, “Best wishes. You are no longer part of the Union. You are under a trade embargo with the United States and the Fugitive Slave Laws are repealed immediately.” It would have taken one heck of a wall to stop the flood of escaped slaves leaving those states, and the Underground Railway to Canada would have been out of business.
After all, our own Declaration of Independence declared that those states had a right to secede. War would have been avoided. Slavery would have survived a few years at most. I suspect that by 1900, the seceded states would have rejoined the Union.
Instead we ended up with 600,000 deaths, Sherman’s March to the Sea, Reconstruction, Jim Crow, and 150 years of resentment, all to preserve the Union, Lincoln’s stated priority. Isn’t that what that killer in Syria is trying to do?