The State Department firmly warns Americans not to travel to certain politically unstable areas of the world. If Americans choose to travel there anyway, it should not be the responsibility of the US taxpayer to pay for their foolishness.
In addition, the helicopter pilots who are ferrying Americans out of Lebanon are risking their own lives to do so. Are the livs of helicopter pilots less important or less valuable than those of arrogant citizens who insist on ignoring the warnings of their own country?
I used to vacation at a ski area out west. The Ski Patrol and the local sheriff's office warned skiers that if they decided to ski off piste and got in trouble, needing rescue, they would have to pay for the rescue team. The cost could go over $50k because helicopters are expensive to run. But every year some dumbass would decide he was such a good skier he could do what he wanted to and nothing bad could ever happen to him. And then the sheriff's department and ski patrol and other emergency personnel would have to spend a mean cold dangerous night out in treacherous country looking for him. And he'd be surprised and outraged when he got a big fat bill for their services.
Same principle. You've been warned; after that, it's on your bill.
We have the same sort of thing here in Arizona... different circumstances, but Every monsoon season, washes fill with rushing water, Then stupid people try to drive through them and get stranded, making rescuers risk life and limb to pull their stupid ass out... but finally a few years back, they started charging people actual costs of rescuing them... I think they even called it the idiot law or something like that.