With what money? US debt is owned by mostly US residents. US defecit is already absurdly high. Not to mention the looming social security failure
With debt, along with the proverbial "cash" comes an opposing "IOU" -- any change* is thus only temporary, in the time dimension (essentially that's what's being exchanged: time)
Printing money out of nowhere is different, because it's missing that other half
* at the risk of stating the obvious: "change" meaning "difference" and not "cents"
* Social security used to have a huge surplus, that was savings that had to go somewhere (even if it was just a savings account in a bank, the bank would then be able to lend it out). They instead buy treasuries and that savings becomes debt to the USG.
* China likewise needs to save dollars because it doesn't want them sloshing around in their economy leading to inflation, so instead of using it to buy things they buy treasuries, and their savings becomes debt to the USG (not always a great deal for China if interest rates are below inflation).
The dollar has been so useful in the past as a currency of trade because you could save large amounts of it easily by buying US treasuries. One reason China doesn't want the RMB to be used so heavily for trade is that they don't want to do the same yet.
When a bank issues debt, the money is created 'out of thin air'. When the debt is paid off, that money is destroyed. However usually more debt is being created than redeemed as things go on, so the total money supply increases (this is a good thing, as it allows the economy to expand).
Various regulations and central bank market interventions (quantitative tightening/easing) control this process, which thus can be induced to 'print money' if the government wishes - assuming they have a sovereign currency.
If you borrow $100 USD from the bank, and pay it off immediately after, it's clear no money was "created" as such
If $100 USD is "printed" outright, it's clear that there's no way to achieve that same result
The fact that the debt isn't generally paid back immediately doesn't change that fundamental. That's what I meant when I said any apparent "change" is about "time" rather than "money"
It is true that the money supply should expand with the economy. Turning raw materials into finished goods represents a larger "net economy" at the end of the process than at the beginning. (Indeed that's basically how it makes sense to have interest on debt in the first place)
Nevertheless, printing money out of whole cloth is different from issuing debt
The bank "printed" money by handing out cash that it didn't have. It only had a fraction of it. That new money went free into the world with the same respect any other cash gets. You and I can't pull that off.
Along with a "-$100" IOU on the books
That is different from merely "printing money"
Which they can use as an asset to create (lend out) even more money that they don't have.
Call it what you want, but the bank is adding money to the economy that wasn't there before.
It's a function of time (mediated by interest rates, subject to market demand, namely liquidity preferences)
That's not the same as outright "printing money" which is not backed by any deposits (what does the balance sheet look like when "printing money"?)