...spending going to interest payments? The government gets nothing for that, no entitlements or anything, just money paid to investors. And don't bring up Bush, we all know he sucked.
There is no economic benefit to The United States of America as long as foreign investors own the debt.
However if we were to sell savings bonds to Citizens of the United States of America who live in The United States of America, at least the interest payments would be cycled back through the economy.