That's why it's called a sacrifice, what all those men and women are doing, for an idea of a country that very few people outside the US would understand.
You'd be surprised how far from the truth you are.
In fact the USA is one of few countries that that faced so few attacks on their soil. Two, to be exact. One almost 200 years ago, and another one (a tiny attack) about 10 years ago. So I'd say it is Americans who have little understanding of an idea of a country.
The US is the only country in the history of mankind that was established to be an empire. Being an empire entails continuous expansion and disregard for other nations. The US certainly has lived up to that ideal and sadly, continues doing so.
And that's why we owe them respect, instead of calling them fools or mercenaries and making glib jokes.
That agree with. Americans owe their troops, and some mercenaries, a lot of oil and other natural resources.