China’s tax rate is considerably higher than 15% and they also don’t want their industries to be competing against companies who are cheating the tax man.
This legislation is directly aimed at preventing a race to the bottom, because societies (represented by their governments) realized that they are getting played by extranational entities if they act alone.
Isn't the literal definition of 'allies' a group of countries which pool their military resources to compel other countries to act how they want? I don't see the contradiction