The US gov tax revenue is $4.9T. According to the CBO (Congressional Budget Office), Mandatory spending will cost $3.7 trillion dollars in 2022. This includes all entitlements and expenditures that are signed into legislation and are considered absolute obligations, such as social security and medicare. Then we add in the estimated $800B of defense spending (which is contractual), and we get a total of $4.5T.
The problem is interest expense itself is currently costing $482 Billion dollars. So we have at least $82 Billion in deficit, which means we have to borrow even more money to pay back the extra interest expense that we can’t pay back. Note that this doesn’t even take into account some of the other discretionary spending as well as unfunded liabilities.
This is true of the current budget, but the US could raise taxes to cover interest payments in the future. The US has relatively low taxes compared to other rich countries. Raising the US tax/GDP ratio to that of Germany would raise about $2T more per year in taxes than the US currently takes in.
One more note. You say
This is true of the current budget, but the US could raise taxes to cover interest payments in the future. The US has relatively low taxes compared to other rich countries. Raising the US tax/GDP ratio to that of Germany would raise about $2T more per year in taxes than the US currently takes in.