When the only other global power has vacated its role and has even become more antagonistic on international issues by veering back towards nativist zero-sum engagements with allies, it allows for new norms of diplomacy to fill growing voids. China has become more assertive because it can. That it is clumsy or discomforting to others may not be their primary concern. Just like economic, political and military advantages that the US or other nations may have afforded them privileges we take for granted even as they irked or angered many.