Elliott Abrams, in this National Review article, highlights a strategy for transitioning Middle East societies marching towards democracy to limit the powers of monarchs (especially those friendly to US interests) and autocrats in the region through legal and constitutional means.
To St. Thomas Aquinas, a monarchy is the best regime. For the rule of an enlightened monarch ruling in the interest of all, guided by wisdom and compassion, without meeting any opposition from the less enlightened ones, is perfect. But it’s rare to find such a being. Plato says that the best regime happens by chance, when politics and philosophy meet, best embodied in a powerful yet wise and compassionate monarch.
Modernity, having indeed given way to institutions and technological inventions that are mass-based (hence, egalitarian, hence, great equalizers), cannot afford to be ruled by a monarch. The individual has become the source of sovereign power, but whose power he equally shares with his fellowmen through a representative government that he and the others empower to represent his and their interests. But that individual together with the rest must be wise, enlightened, and just. And insofar as he and they are ruled sometimes by unruly passion and prejudices, a representative government provides the mechanisms with which to check such excesses. This is the meaning of genuine republicanism.
But in the absence of the above conditions, of a people who is habituated in the ways of self-rule, the next best thing for countries ruled by monarchs and autocrats is constitutional monarchy.