No longer are diplomatic power struggles between nations played out in intense negotiations and high stakes summits. Instead, it's all in the handshake.

Donald Trump had left Shinzo Abe, the Japanese prime minister, reeling after a 19 second handshake last week in the White House.

Before that, the US president had grasped Theresa May's hand in an act that was splashed across the front pages as a sign of the "special relationship".

Donald Trump shakes Justin Trudeau's hand outside the White House - This content is subject to copyright.

So when Justin Trudeau, the Canadian prime minister, became the third world leader to visit the White House on Monday, all eyes were on the all-important shaking of the hands as they met outside.

Pres. Trump greets Canadian Prime Minister Justin Trudeau at the White House https://t.co/DYel2taCiVpic.twitter.com/F8OVvXDyEm — ABC News Politics (@ABCPolitics) February 13, 2017

"Quite amazing," wrote one Twitter user. "Look at the battle going on in that handshake as Trudeau resists the Trump 'grip and yank'. To the gym world leaders!"

According to some students of body-language, Mr Trudeau appeared to deliberately "cut off Trump's leverage" to deter any strong-arming one-upmanship.

"Notice how Trudeau does the 'alpha shoulder grab' before Trump can do the 'alpha rip his arm off' handshake," one noted on Twitter.

Trudeau resisting Trump's weird handshake is the biggest display of dominance in the history of Canada — Brandy Jensen (@BrandyLJensen) February 13, 2017

"Trudeau resisting Trump's weird handshake is the biggest display of dominance in the history of Canada," another wrote.

Check muscle flinch at 0:06

Trump tries his macho arm-yank handshake thing

But he gets nowhere, due to Trudeau's single-arm dumbbell rows https://t.co/DtQH2U5Xj9 — Jonathan Kay (@jonkay) February 13, 2017

One Twitter user went as far to call it one of Canada's greatest victories.

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#TheResistance



The handshake question. Some say Trump didn't try his strong arm jerk & pull. I think he did, but Trudeau is wicked strong. pic.twitter.com/bZxFty84J6 — The Anti-Trump (@IMPL0RABLE) February 13, 2017

The Trump-Trudeau handshake has happened. Just look at the power struggle there, Trudeau has been well briefed. https://t.co/MsAEvtTNQ2 — Alistair Coleman (@alistaircoleman) February 13, 2017

.@ABC@katiecouric THE STRENGTH of the Trudeau's HANDSHAKE. What a MAN, he avoids the #TrumpJerk w/ pure maple leaf strength. Strong leader — Seena Jon (@seenajon) February 13, 2017

Once inside, the pair battled once more, this time with a perfunctory shake lasting just a few seconds - and none of Mr Trump's trademark tugging.

But while that handshake was fairly unremarkable, Mr Trudeau's expression before taking Mr Trump's hand provided an unmissable opportunity for Twitter's army of indefatigable mickey-takers:

"I went to Crowborough, East Sussex and all I got was this lousy toy giraffe." pic.twitter.com/F6dvC2x3PH — Nick Harvey (@mrnickharvey) 13 February 2017

The two leaders, who attended a roundtable discussion about the advancement of women in business and a working lunch, are polar opposites.

Mr Trump, 70, is a celebrity businessman who rose to fame on reality television. The sprawling Trump organisation has international real estate holdings, marketing deals and golf courses.

Mr Trudeau, 45, is former high school teacher, nightclub bouncer and snowboarding instructor, who grew up in politics. His father, the late Prime Minister Pierre Trudeau, was one of Canada's most famous politicians, a liberal legend credited with making Canada what it is today

Profile | Justin Trudeau