WI: Post-WW1 U.S. mandates over Armenia and the Straits?

[World Mapping]

IOTL, Britain planned to offer the United States mandates over Wilsonian Armenia and the Turkish Straits post-WW1. These never came to be, but what if they did? How would this affect Turkey, the Entente, and the rest of the world?

 

[Wendell]

The gambit would be enough of a colossal failure as to make the US even more isolationist come the 1930s and 40s.