China's plan for a new $300 billion sovereign wealth fund is as much a warning to Washington as it is a body blow to Brussels.

It's the clearest sign yet of Beijing's waning faith in bonds issued by Europe and the United States. Europe's festering debt debacle, record low yields on US. Treasuries and a depreciating dollar all add weight to the view in China that the time is ripe to change investment tack.

Beijing has watched for two years as Europe's crisis has choked growth and demand in China's biggest export market and stoked default risks on the near $800 billion of euro zone government bonds it is estimated to own.

The $300 billion figure is consistent with the sum that experts calculate China has in excess reserves - the amount beyond what Beijing would need to tackle a balance of payments crisis or a domestic funding emergency.

Granted, Chinese investors won't be warmly received everywhere - a sovereign wealth fund showing up in Paris or Madrid with an offer to buy up public infrastructure would probably come away disappointed.

But with a European debt crisis and the US triple-A rating no longer a given, China's state investors have good reasons to push into new kinds of assets.  

Whether China's change of focus is all borne of European debt and dollar debasement or a desire to move China's economy up the value chain, a new mood in Beijing is evident to many.

It's at least the best time in 15-20 years to buy European listed equity, even adjusting for the tattered price-tags on European financial stock, says JP Morgan analyst Mislav Matejka.

Euro zone shares are trading at a 46 percent price-to-book value discount to the United States, making it the cheapest region in the world for a global equity investor,.