That's simply false. https://en.wikipedia.org/wiki/Quantitative_easing#After_2007
Japan, Switzerland, Sweden, the UK, the Eurozone...
The EU injected €2.4 trillion in this fashion over a four year period. (https://www.independent.co.uk/news/business/news/ecb-money-p...) $12B is nothing.
>No other country can do that without going into hyperinflation.
Other CBs have significant enough credibility or special situations where they can print comparable money without setting off hyperinflation. Definitely Japan's and probably Europe's.
It turns out warfare is extremely expensive (see also: guns v. butter) and one of your line items is buying off local warlords.
It's worth something because the people using it feel it's worth something, and that's true for non-fiat currencies as well. Bitcoin and gold are non-fiat, but still heavily depend on demand to determine their value.
"$12 billion in U.S. currency was transported from the Federal Reserve to Baghdad in April 2003 and June 2004, where it was dispensed by the Coalition Provisional Authority. A Vanity Fair magazine report concluded that of this sum, "at least $9 billion has gone missing"" [1]
$12 Billion in cash!!
[1] https://en.wikipedia.org/wiki/Allegations_of_misappropriatio...
[2] https://www.youtube.com/watch?v=q6vi528gseA