U.S. not evacuating all Americans from Sudan. Here’s why

Warring factions trying to seize control of the east African nation of Sudan have plunged the country into chaos, and thousands are fleeing the capital of Khartoum and nearby battle zones. Some countries, including the U.S., have shuttered their embassies and many are coordinating daring evacuations of their staffs and other residents in an array of convoys, flights and frantic getaway drives.

But over the past week there have been dramatically different responses by various…