To be fair, the average maturity of U.S. debt is something like 70 months and an interest rate spike only impacts new debt or roll-over debt, not the outstanding debt. So if it indeed "spikes", which would be a sharp up followed by a sharp down back to something like current levels it would have minimal impact on that $300 billion per year number since it would only impact new debt issued during the spike. If it went up and stayed up, it would certainly have a greater impact, although again arguably that would indicate an inflationary period which has the overall impact of reducing real debt. And it would take 70 months to be fully felt. And that's before we even start considering that 30% of the debt is intergovernmental so higher interest just means more interest goes to things like the social security trust fund. Not a simplistic issue that can be reduced to a single number.
Life goes on even if you are technically insolvent or in default.
extrapolating from one example to a general rule is an error to logic. countries will pay a high price for such foolishness. think venezuela, argentina. dont think the economic malaise of these counties, product scarcity,high inflation and low productivity cannot come to europe or america.
