Stephen Biddle probably isn’t a household name, but he’s a pretty serious player on foreign policy. Biddle is not only a senior defense policy analyst at the Council on Foreign Relations, but he’s also served as an advisor to Gen. David Petraeus.
Without getting in to his arguments or my reservations, I just wanted to lay out Biddle's best case scenario as he presented it: if everything goes right and if the US continues to "hit the lottery" with the spread of local ceasefires and none of a dozen different spoilers happens, then a patchwork of local ceasefires between heavily armed, mistrustful communities could possibly hold if and only if the US keeps 80,000-100,000 troops in Iraq for the next twenty to thirty years. And that's the best case scenario of one of the current strategy's smartest supporters.
Remember, Buddle's one of the optimists. This is a best-case scenario.