Iraq is a false construct. Like the African states, this would collapse as the borders are arbitrary with tribes spilling over. You have Kurds in the north who have peoples in Turkey, Syria and Iran. You have Shias in the south who are more tied to the Shia Arabs in Eastern Saudia. You have Assyrian Christians who are spread (or were spread) around Mosul. And you have Sunnis who are closer to the Sunnis in Eastern Syria. You had 3 separate Ottoman provinces stitched together by the English
Then you have Lebanon which should have been 3 separate states but was stitched together by the French
This was the same as the false durand line that split Pathans between Afghanistan and Pakistan
I understand your point about constructs.
I’m not exactly sure why the nations were stitched together like they were by Britain.
It was a different time. The world was a lot larger. It may have made sense at the time, but in a way the area has turned into a time bomb waiting to go off every so often.