I think that the waning American Super Power status will inevitibly bring about an end to their role as the ‘Global Policeman’.
Seems that all dominant empires have played this role at the height of their powers, as did the British Empire (Arrr *sigh*)
On the one hand it’s an attempt to promote and spread what they would see as common values. Most of the time though this Global Policeman role is thoroughly tied up with its own economic interests i.e. US-lead Iraqi Invasion/Oil suppply…, British Colonisation of more-or-less everywhere/exploitation of natural resources in Africa and India.
I don’t doubt that China will police it’s interests in the same way.
The upside is that the Chinese may find it easier to build relationships with nations that previously have had little rapore with the The WestTM
The downside will be continued deals with dodgy regimes to allow it to extract resources it badly needs at the expense of The Environment/Human Rights etc
So essentially….., no change whatsoever! 
In the words of ‘Won’t get fooled again’ by the mighty WHO;
“Meet the new Boss. Same as the old Boss!”