For a social gesture that goes back some three millennia, the handshake has recently garnered a good deal of attention. Or, in this case, two handshakes separated by nearly 10 years between the same two men: U.S. President Donald Trump and French President Emmanuel Macron. You might recall the first of these encounters. In 2017, at the opening of the NATO meeting in Brussels, Trump and Macron—both fresh off election wins—met for the first time.