I don't necessarily agree but he makes the point that monarchs seem to survive much better in the Arab world than do dictators.
He argues that some of the monarchs, such as King Hussein in Jordan and the Royal Saudis (and a few others) have long historical roots in their societies. Some claim to go back to Mohammed.
His point is that monarchs have legitimacy derived from the divine right of kings. Whereas dictators lack legitimacy. Even when the dictator was originally elected, his inability to have new elections voids his legitimate connection to the society.
I can think of a few counter examples. However Abrams point is that any government needs legitimacy in order to survive.
That is why the Bush doctrine, and the military success in Iraq have long-term positive objectives. By establishing the validity of democratic elections as a source of governing legitimacy, the United States has introduced, to the Middle East, the core idea that supports democracy.