In Western societies, the handshake became evidence of a binding contract to buy and sell. It could also signal a truce or peace agreement between warring parties. Informally, it was a way of welcoming a stranger.

Like many other practices, President Trump has upended this friendly gesture of respect. In shaking the hand of recently appointed Supreme Justice, Neil Gorsuch, Trump appeared to want to pull Gorsuch off his feet.

Handshakes between President Trump and the leaders of our allies have descended to wrestling grips. Some appear to cause actual physical pain to Trump’s handshake partner.

As leaders have wised up to Trump’s apparent understanding of handshakes as another form of warfare, they have developed strategies to deal with it.

French President Emmanuel Macron gripped Trump’s hand as hard as Trump gripped his. Trump appeared to slightly wince while Macron grinned. Macron later commented, “One must show that we won’t make little concessions, even symbolic ones.”

Canadian Prime Minister Justin Trudeau, an amateur boxer, also came off well in the handshake match.

Since most leaders of our allies are younger than Trump, time would appear to be on their side.