That's according to credit rating agency Moody's. In a quarterly report about sovereign debt, Moody's analysts wrote that despite market worries about rising government debt levels, there is "no imminent rating pressure" for the United States and other big governments carrying its highest triple-A rating.

But the report added that these governments' margin for error "has in all cases substantially diminished," thanks to a weak outlook for economic growth and enormous debt loads taken on to quell the financial meltdown of 2008-2009.

Cutting back on public spending too soon risks a double-dip recession, Moody's said, while leaving stimulus measures in place too long could lead to a sharp rise in interest rates "with more abrupt rating consequences a...