It's like beauty, apparently...  

I have posted before about the lack of "safe" assets for very conservative investment purposes. It's not getting any better.

The global pool of government bonds with triple A status from the three main rating agencies, the bedrock of the financial ­system, has shrunk more than 60 per cent since the financial crisis triggered a wave of downgrades across the advanced economies. The expulsion of the US, the UK and France from the “nine-As” club has led to the contraction in the stock of ­government bonds deemed the safest by Fitch, Moody’s and Standard & Poor’s, from almost $11tn at the start of 2007 to just $4tn now, according to Financial Times analysis.
The shrinkage, largely a result of US’s downgrade by S&P in August 2011, is part of a dramatic redrawing of the world credit ratings map, which is encouraging investment flows into emerging markets and forcing investors and financial regulators to rethink definitions of “safe” assets. [More]

What I wonder is if the ratings agencies aren't playing with fire here by thinking they have the power to label and render judgment on assets. If US debt is downgraded and people still flock to buy US treasuries, don't ratings agencies risk being seen as irrelevant?

More worrisome (for them) is if another metric, by another self-proclaimed referee catches on instead. Safe could be in they eye of the beholder and we change our rules to fit.