Money begins its life by being spent by the federal government.

No, in the modern system, money is created by commercial banks when they give a loan.

At the moment a loan for $1 million is created, a bank takes $0 and then turns it into two accounts: a loan with a balance of negative $1 million owed, and a deposit account with a balance of $1 million that can be withdrawn. From the bank's perspective, and the borrower's perspective, they went from having $0 to suddenly each having $1 million in assets and $1 million in liabilities, for a net value of zero. Obviously there are going to be fees and stuff paid out, and interest charged over the life of the loan, but you can think of that as fees for services rendered.

The money in that deposit account, created out of thin air, can then be spent elsewhere and enter the economy.

The limits on the ability of banks to do that indefinitely is default risk (the bank is left holding the bag if the borrower doesn't repay) and liquidity (the bank needs to be able to use the loan balances as an asset on its balance sheets to go and borrow cash for its own operations so that its accountholders always have the ability to withdraw money on demand) and government regulation (the Federal Reserve and the FDIC have various regulations requiring their balance sheets to be able to survive stress tests and other adverse economic events).

So even though the government, through Federal Reserve policy, controls how private market participants might choose to create money, the actual act of money creation happens in the banks, not in the government (except when the government is acting as a bank by lending money through its loan programs).

For the benefit of non-Google users, here is the unshortened URL for that Bank of England article: https://www.bankofengland.co.uk/-/media/boe/files/quarterly-bulletin/2014/money-creation-in-the-modern-economy

With that said, while this comment does correctly describe what the USA federal government does with tax revenues, it is mixing up the separate roles of the government (via the US Treasury) and the Federal Reserve.

The Federal Reserve is the central bank in the USA, and is equivalent to the Bank of England (despite the name, the BoE serves the entire UK). The Federal Reserve is often shortened to "the Fed" by finance people, which only adds to the confusion between the Fed and the federal government. The central bank is responsible for keeping the currency healthy, such as preventing runaway inflation and preventing banking destabilization.

Whereas the US Treasury is the equivalent to the UK's HM Treasury, and is the government's agent that can go to the Federal Reserve to get cash. The Treasury does this by giving the Federal Reserve some bonds, and in turn receives cash that can be spent for employee salaries, capital expenditures, or whatever else Congress has authorized. We have not created any new money yet; this is an equal exchange of bonds for dollars, no different than what you or I can do by going to treasurydirect.gov and buying USA bonds: we give them money, they give us a bond. Such government bonds are an obligation that the government must pay in the future.

The Federal Reserve is the entity that can creates dollars out of thin air, bevause they control the interest rate of the dollar. But outside of major financial crisis, they only permit the dollar to inflate around 2% per year. That's 2% new money being created from nothing, and that money can be swapped with the Treasury, thus the Federal Reserve ends up holding a large quantity of federal government bonds.

Drawing the distinction between the Federal Reserve and the government is important, because their goals can sometimes be at odds: in the late 1970s, the Iranian oil crisis caused horrific inflation, approaching 20%. Such unsustainable inflation threatened to spiral out of control, but also disincentivized investment and business opportunities: why start a new risky venture when a savings account would pay 15% interest? Knowing that this would be the fate of the economy if left unchecked, the Federal Reserve began to sell off huge quantities of its government bonds, thus pulling cash out of the economy. This curbed inflatable, but also created a recession in 1982, because any new venture needs cash but the Feds sucked it all up. Meanwhile, the Reagan administration would not have been pleased about this, because no government likes a recession. In the end, the recession subsided, as did inflation and unemployment levels, thus the economy escaped a doom spiral with only minor bruising.

To be abundantly clear, the Federal Reserve did indeed cause a recession. But the worse alternative was a recession that also came with a collapsed US dollar, unemployment that would run so deep that whole industries lose the workers needed to restart post-recession, and the wholesale emptying of the Federal Reserve and Treasury's coffers. In that alternate scenario, we would have fired all our guns and have lost anyway.

You're mostly correct, but I would like to add a piece that not everyone understands.

The government issuing debt can be good for the government because of inflation and economic stimulus.

When the government sells debt, it sells $ in the future for a different (usually lower) price today. It doesn't actually pay interest, the effective interest is determined by how much the market is willing to pay for it.

Lets say the government sells a billion dollars worth of bonds, which will pay out in 20 years, they sell it today for three quarters of a billion dollars. Sounds like a bad deal, right? The government is clearly losing a quarter of a billion dollars.

Except, the government doesn't have to pay it back with money from today, it pays it back with taxes it will earn 20 years from now. If in those 20 years, inflation is say... 3% on average. Lets just ignore compounding to make it simpler, and say the costs of everything goes up by 60% over those 20 years. Assuming the tax rate stays the same (and ignoring compounding effects) they'd be collecting 60% more actual dollars than they would today. Paying back a billion dollars from taxes at that point is now easier than it would have been to try to raise 750 million from taxes today.

The government just "made" money by borrowing money. Really, it comes from inflation eating away at wealth, which is why the government printing debt like this usually causes inflation. All things inflating equally is a wealth tax.

Side note: The current inflation issues we're seeing are not happening equally; wages are not going up as fast as inflation on common necessities like housing and groceries. That's a different problem, not caused by government debt printing.

Then there's the economic effects of spending the money now. More economic activity today usually means more taxes collected overall throughout the years that whatever they spent the money on benefits people. A new bridge or road, better air traffic systems to allow more flights, safer oceans to protect shipping, etc.

Where do dollars come from? Is there any limit to how much money the government can create?

Why doesn't the US govt print USD to cover its deficit instead of borrowing?

How high can the debt to gdp get before the economic system collapses?

I do forsee the US not being able pay debt in 10+ years and nobody will lend them anymore money.

How do governments deficit spend?