Backed by a government means that it's backed by the ability of a government to tax work and production happening in the country. Every year the US government

Backed by a government means that it's backed by the ability of a government to tax work and production happening in the country. Every year the US government collects about 25% of all economic activity as taxes payable only in USD. Every person and business in the country must sell on average 25% of their productive output for USD, and you can buy all those things with USD.