debt to GDP is, of itself, meaningless as a metric, and you know it.
there are three basic components to debt. the first is how much you owe. the second is what is the rate of payment, in terms of interest. the third is the due date to retire the loan. add another important component...to whom you owe the money.
if i borrow 1000 dollars, and i pay 2% interest, and have 30 years to pay it off, that is a far different case than if i am paying back at 10% interest and i have to pay it off by the year?s end. debt repayment is not static analysis. if the payment rate is 2%, and my salary increases at 3%, that is far different than if i lose my job, and have top repay from savings. also, you have not told us how much is government debt and how much is sovereign debt. borrowing from a loanshark and borrowing from your family has different undertones.. much of the US debt is owned by entities like Social Security. if the debt becomes unmanageable, the government can raise the eligibility by 2 years and shave a few trillion off the debt. this is not like Greece borrowin from Germany, in which the currency and interest rates are fixed. the US has a number of monetary options to deal with debt. besides, a country like Japan has been running numbers like 180 to 200 for nearly a decade, and is still borrowing the cheapest money. the economy is not in the tank for it.
it means something to small developing countries, whch have minor economies, and who borrow in foreign currency. when your currency is the world reserve currency, and your treasury bills are the most reliable on earth, your debt has very little to do with the economic performance. just look at the response to the downgrade of the US credit rating a few years back. it never did a thing to the US ability to borrow.