While you're being pedantic... the Treasury actually issues debt in the form of Bonds and Bills. Many of the bonds are bought on the open market both privately in the USA, and overseas, by countries like China that have massive trade deficits with the US and use their money to buy US debt, rather than US goods. The Fed, which attempts to control inflation, buys US Treasury issued debt in whatever manner they see fit... if they need more money to buy more debt, then the Treasury prints more currency. It's a rather symbiotic relationship.