Yes, it rests largely on the trust and faith you have in the currency. At a basic level, you at least need to trust that your money won’t lose half its value overnight. Otherwise, you’d just use another currency; there are a couple of examples in recent history. Now, whether your faith is justified or not is another question. Then you can look at the size of the economy or the power of whatever is backing the currency.

> The value of my past work being tied to the success of something I have no control over, a machine that murders innocent people in drone strikes across the world?

Such is the world we live in, whether we like it or not. As a side note, a lot of the drone murdering is done more or less transparently for economic reasons. Yes, a government powerful enough to project power on the other side of the planet to secure a good supply of cheap oil or to ensure some form of hegemony does inspire confidence in its currency. I wish it weren’t so, but here we are.