Obama topples the Assad regime in 2013

Bashar al-Assad could easily be (and mostly still is) a bastard like Gaddafi and Saddam were, but still he is a 'civilized' and 'secular' leader. Whatever iron-fisted brutes Saddam and Gaddafi were, they still were better than total fustercluck boiling now in (former) Iraq and (former) Libya.

As for me, secular tyrants with hospitals, schools and working infrastructure and social services are indisputable better than XVII-century-like tribal and narrow-minded warlords (and their respectable daredevil Sharia governments).

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Russia would do nothing, just sit down and exclaim against all of this in the UN along with China. Iran would probably be involved in the proxy security raids.
Putin just doesn't have the mentality to strike sparkles with EU/USA.
Syria would be just consumed by civil war madness in all its ISIS gory and glory.
This is somewhat of a myth that there is a clean divide between the religious cleric fanatics and the secular tyrant. The "secular tyrant" often gets into religious matters as evidenced by Saddam's behavior in the 90s to shore up Sunni support after the disasters of '91, and how Assad openly depends on the support of the Shiite extremists in Lebanon and Tehran for arms and troops. Even Sisi, the Egyptian dictator, makes spiritually (and pretty theological ignorant) based statements to justify his repression. On the other hand, so-called religious fanatics in charge of the Saudi and Iranian states have made secret police tactics recognizant of secular tyrants part and parcel of their routine.
 
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