[Royal personages] do not have the right to receive physical obeisance from American citizens. Miss Manners has had to issue the decree many times now that American ladies should not curtsy [ed: nor should American gentlemen bow] to royalty, and there are still those who do so at every available opportunity. They are in error, not only in the matter of world etiquette, but of geography, physics and ancient and modern history. . . . Bending the knee is the traditional gesture of an inferior to a superior. . . . The curtsy is but one form of the gesture of adoring a sovereign. . . . Thus, those who believe that curtsying demonstrates their own high social rank or breeding are mistaken. Their geography is faulty if they think that bending down will elevate them; the notion that there is a law of physics stating that what goes down must come up is erroneous. As for history, Miss Manners considers that the matter was settled by the philosopher Callisthenes, who disabused Alexander the Great of the notion that the Persian custom of groveling to royalty could be established in Macedonia and Greece. . . . If you require more recent history, there is that matter of the war that we Americans fought to free ourselves of subjugation to the British Crown. . . . How, then, do we Americans properly treat royalty? With the dignity and respect we naturally show to heads of state and other foreign officials. Our traditional form of greeting is to shake the hand. This gesture is not interchangeable with that of the curtsy [ed: or bow, or genuflection], as the State Department once tried to suggest when obfuscating the matter, claiming that the word "curtsy" being derived from "courtsey," it signified no more. Your government should not have to inform you that the word "courtesy" derives from behavior in the courts of royalty, which is no business of ours.
~U.S. President Barack Obama visits King Abdullah bin Abdul Aziz Al Saud in Saudi Arabia in June, 2009
~U.S. President Barack Obama visits Emperor Akihito and Empress Michiko in Japan in November, 2009
Update, 24 Nov. 2009:
~U.S. President Barack Obama visits Chinese Premier Wen Jiabao in China in November, 2009