We see how well this is working out in South Africa.
It is not working in SA because they do not have physical separation and the ANC has not relinquished claims in perpetuity.
This actually would be a very good solution for the Boers, but the other side would be crazy to agree - and they won't.
If DeKlerk was going to surrender anyway, he should have negotiated a "good fences make good neighbors" agreement up front. Now it's probably too late.