It must be said for the last time and everyone should accept that and do not ask stupid questions: formally all heads of state are equal, regardless of the nature of their position. The Emperor of Japan, the Prince of Liechtenstein, the Governor-General of Canada, the President of Nigeria and the President of the United States of America are of equal status and do not need (and should not, I think) to bow to anyone. The consorts of heads of state enjoy their status, even if they are not Queens but only First Ladies or Vice-Regal consorts. Of course, anyone should show his or her respects to somebody if he or she wants it and thinks it is appropriate. But there is a difference between me, a commoner, choosing to show my respects to a foreign monarch or a prince or anyone on a high position, and an official, someone who holds this high position. Should Obama bow to Akihito? Maybe he wanted it, because of Akihito's age, the history and tradition of the Imperial throne and Japan at all, but really, did he? From an American view? From protocol view? It's not so easy. Generally, I do not want my President (I'm from Poland) to bow to anyone, because he is for me the highest representative of Poland. Poland is a sovereign and proud state and should not bow to anything or anyone and thus, its President should not. Of course, he is not the state himself, like in the absolute monarchy, but the symbolic role of the Presidency is clear and very important.
I have to make some pertinent corrections to the above concerning British court protocol. All princes and princesses of the blood and their spouses bow or curtsey to the soverign; a prince or princess does not bow to Prince Philip - he is not a constitutional prince consort. Although the current royal family and a few remaining families adhere to the tradition of kissing (something the late Queen Mother didn't like, but then she was from a landed coal owning aristocratic and not a royal background) the hand of a lady of rank, kissing her left cheek if a close friend, and kissing both cheeks if a kinswoman; doing all three if she is a close kinswoman of high rank. The misplaced political correctness of the established elite thinks it fine not to bow or curtsey. Quaint custom? Next week a new Prime Minister will be appointed by the Queen and believe me if he were not to kiss hands then that would be a constitutional crisis. Perhaps those seeking power have always been prepared to bow the knee!
That's true. I saw some pictures of Michael of Kent bowing to his cousin The Queen and the Duke of Windsor bowing to his sister-in law The Queen Mother as well as his niece The Queen. There also photos and videos of royal relatives kissing, as you wrote, hand and both cheeks of their kinswomen, for example, the former King of the Hellens kissing the hand and both cheeks of Elizabeth II. It was Getty Images, I think.
