Egypt Is Population Dominant In the Region

I'd planned on doing this myself, but Yglesias has already done the work.

Algeria and Iraq have experienced regime change relatively recently, making those regimes probably less prone to being displaced than elsewhere. I would also add North Sudan (a bit under 30 million), Libya (6.4 million), Morocco (about 32 million), and Western Sahara (about 400,000) to his list.

I also note that the term "Arab" as used by Yglesias is basically a political self-identifier (as in the "Arab League") and as a proxy for a significantly Arabic language speaking population, rather than ethnically Arab populations.

The populations of North Africa and Egypt respectively are mostly not members of the same ethnic group as the once nomadic people of the Arabian Peninsula, despite their strong cultural affinities to each other relative to the rest of the world. While all of these populations historically spoke Afro-Asiatic langauges, prior to the expansion of the Islamic empire (ca. 700 CE plus or minus a few decades) the North Africans spoke mostly Berber languages, the Egyptians spoke mostly Coptic languages, and the Arabs spoke Semitic languages. The Islamic empire's expansion was not a population replacing one; mostly it grew by rapidly assimilating existing populations into new languages, religions and cultures.