That's true. The US doesn't cover the cost of evacuating its nationals out, any more than it covers the cost of you going oversees.
I just saw this and I have a problem with it. If we can pick up the tab for rescuing, with military helicopters, the many residents of New Orleans, who were given days of notice and ignored directions to evacuate, then I think we can justify evacuating our stranded Americans overseas.
If the enemies of our country think we will abandon our citizens so readily, they will be embolden to strike areas where Americans are located to an even greater degree.
Our military is tasked with defending our country and that includes our citizens. Since the SCOTUS has been so liberally extrapolating from our U.S. Constitution, one could say that the Fourth Amendment ["The right of the people to be secure in their persons..."] could be applied globally.