Why not question viability replacing despot's iron will over middle eastern tribes?

This is not the first administration to find itself absorbed by a book on Vietnam. When President Barack Obama contemplated sending more troops to Afghanistan, he and his staff read “Lessons in Disaster,” by Gordon M. Goldstein, an account of McGeorge Bundy, the national security adviser to Johnson. The book found that Johnson had failed to question the underlying domino theory that the fall of one country to communism would lead to others.

If failure to question the domino theory caused the escalation of Johnson's Vietnam war effort then failure to question the theory we are able to replace by force a despot's iron will over various middle east tribes with a unified and democratic government causes our continual grind in warfare. Let Iraq and Syria balkanize as they will and support diplomatically and with humanitarian aid those regions that govern successfully.