Jamal was at his most powerful at the end of 1.5, when he apparently killed the Sheikh. We find in 1.6 that he didn't quite do it. And it takes Barry to step up and make the murder complete. This epitomizes the relationship between Jamal and Barry that is at the heart of this series: Jamal is an incomplete tyrant. He needs Barry to lead fully and effectively, including killing a mortal enemy.
But Barry doesn't see things that way, and his killing of the Sheikh, to clean up his brother's mess, pushes him over an edge he was already hovering close to. Jamal may need Barry, but what does Barry get from Jamal? Not much, except deadly predicaments that Barry has to think his and the country's way out of. And that being the case, wouldn't it be easier for Barry if Jamal wasn't there at all - leaving the country totally Barry's to rule?
The irony is that Jamal was the verge of going to the Maldives, if not with his wife than with the beautiful blonde American. He was already all too ready to leave Abuddin anyway. But with the Sheikh out of the way, he can stay. He kills the blonde, presumably to leave no trace - other than his wife Leila - of his desire to leave the country. But what that murder most shows is the depravity of Jamal. The attempted killing of the Sheikh at least had a political motive. The smothering of the blonde has a much greater ratio of sociopathy.
Leila has a crucial role in the near future of all of this, as well. She was proud of Jamal when he told her what he did to the Sheikh. Her thoughts about Barry when Jamal tells her what Barry did to the Sheikh were not as clear, but there was presumably some admiration there, too.
So, with Molly out of the country, and Jamal pushed out of the Presidency by Barry, what will Leila do? Likely try to get together with Barry - if the story goes that far in that direction, which will be fun indeed to see.
See also: Tyrant: Compelling Debut ... Tyrant 1.2: The Brother's Speech and His Wife ... Tyrant 1.3: A New Leaf? ... Tyrant 1.4: Close to the Bone ... Tyrant 1.6: Don't Mess with Jamal
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