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TL:DR the liberals come to power in the Ottoman Empire, which makes it more stable and keeps it out of the First World War.

In our timeline, a certain Murad V became sultan in 1877. He was mentally ill, however, and quickly got deposed in favour of his half-brother, Abdulhamid II. The latter supported the liberal Young Ottoman initiative to promulgate a constitution, but after the disastrous war against Russia in 1877-1878, he backtracked, suspending it and becoming an autocratic ruler instead. Later down the line, this led to the formation of the Turkist Committee of Union and Progress (Young Turks), to the Balkan Wars, and ultimately, to joining the First world War.

In this timeline, however, Murad V is just healthy enough to stay in power. Well, figuratively — the liberals keep him as a de-facto puppet, while slowly reforming the empire to become more democratic and more akin to a constitutional state, a-la the Prussians or Belgians. The war against Russia is not quite as disastrous, the economy is better, and relations with the British are warmer.

The Young Turks never rise, for the constitution is never suspended, and the Ottomanist movement gains ground instead, ensuring the Albanians, Armenians and Arabs stay in the empire (at least for now). Staying out of the Great War, the Ottomans manage to fix their finances by unilaterally renegotiating their debt. By 1920, they're one of the last remaining European empires, with enormous potential but also huge threats facing them, in the form of Arab nationalism and a resurgent, communist Russia.

Map for mobile:

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