In the second photo, taken over forty years later, we have US President Barack Obama making a similar visit to China. This time, again literally as well as figuratively, Mr. Obama is on the left and Chinese President Xi Jinping is on the right.

Over the ensuing four decades, both countries have been changing dramatically. The US has become increasingly socialistic, more focused on Big Government and more of a totalitarian state. In 1972, it was the world's foremost creditor nation; it is now the world's foremost debtor nation. By contrast, China, since the death of Chairman Mao, has opened up considerably, with billions of people becoming upwardly mobile, in response to China becoming increasingly capitalistic.

To be sure, both countries retain some of their historical features, but increasingly, the US is acting like a country in decline, whilst China is acting like a country on the rise.