I’ve just watched the inaugural oath and speech in London — not too far, as the crow flies, from Buckingham Palace. A French friend was sitting next to me; some Brits were wandering in and out of the room, hanging around to see if anyone famous had started singing yet. All of us marveled at the seamless way in which U.S. pop culture, high culture, history, politics and national symbolism were so effortlessly melded together into a single event.

(John Stillwell/Getty Images)

Because there isn’t anything like it in any European country — prime ministerial swearing-ins are business-like affairs in most European countries — we tried to think of what else it might resemble, and the best I could come up with was the recent royal wedding. The marriage of the Duke and Duchess of Cambridge was, like Obama’s inauguration, carefully designed to evoke the glorious past and the bright future, to display the ancient symbols and to help young people engage with the national story. Will brought Kate into the royal family; Obama brought Beyonce onto the steps of the Capitol.

Of course there is an extra element in an American inauguration, which is the intervention of American voters. Will and Kate will become king and queen thanks to luck, genes and history. Obama remains president — and his predecessor will become president — because of a long institutional process designed to get the approval of the majority. That gives him the legitimacy he needs to govern, as opposed to merely posing on the covers of fashion magazines.

Yet the ceremonies which our nations require are nevertheless similar: Whether in monarchies or republics we all want to see that same combination of old and new national symbols displayed when there is a new, or renewed, head of state. If Obama had just said an oath in private and disappeared, Americans would have felt cheated — just as Brits would have felt cheated if Will and Kate had eloped.

Myself, I always feel better about the president, whoever he is, after watching him go through the sometimes ludicrous pomp and ceremony of an inauguration, and I expect others do too. Presumably, that’s why we organize them.