Wonder where the world would be now if those dead english guys had divided the Ottoman Empire Kurds with Kurds, Armenian with Armenian, Aramaic with Aramaic, Shiite with Shiite, yaddah yaddah. Hhhmmmm......
Oh, they'd still be choppin' each other up but it would be across borders instead of civil wars. Now if that had happened the carpet bagging royals put in place by the English (Saudi Arabia, Trans-Jordan) would have probably been ethnically cleansed long ago in countries where they couldn't play one group against the other as easily as they have in their current artificial states.
Speaking of which did you ever notice the huge inferiority complex of Arab rulers? They all want to marry Western women and act like European nobles from the 19th century.
Not as easy as it sounds. Every community goes for maximalist borders. Inter-communal struggles break out as majority communities attempt to persuade minorities now felt to be fifth columnists to leave via beatings and pogroms. The British partition of its South Asian holdings into India and Pakistan resulted in 1m dead. Muslims attempted to regain the sway they had held and felt entitled to under the (Muslim) Mughal dynasty that had preceded British rule. Hindus wanted the freedoms that preceded Mughal rule. So they thrashed it out in the streets, and millions of refugees ran the gauntlet all the way to the (newly-defined) border and beyond, of lands they had never seen before.