Donald Trump is taking on world leaders in genuine hand-to-hand combat.
Across the globe, prime ministers and presidents are being coached by their strategists on how to handle the Trump handshake.
Trump likes to seize peoples' palms in a bone-crunching grip, then drag them into his personal territory in a rip-your-arm-off wrestling move.
His latest duel was with French President François Macron, who outlasted Trump in a marathon white-knuckle squeeze session, as reporters gaped.
Macron refused to release Trump's hand until Trump blinked - er, flinched.
Some world figures haven't fared as well, notably Japan's Prime Minister Shinzo Abe. His digits were seized-and-squeezed by Trump for 19 awkward seconds, while the Japanese PM visibly tried to wriggle free – and rolled his eyes.
Trump Supreme Court nominee Neil Gorsuch was yanked toward Trump's body and jerked around like a marionette. (Ex) FBI Director James Comey hid behind a curtain trying to avoid being man-handled by his then boss.
Prime Minister Justin Trudeau met with U.S. President Donald Trump in the Oval Office of the White House, in Washington, D.C., on Monday, Feb. 13, 2017.
The cleverest handshaking head-of-state was Justin Trudeau, who braced his other hand firmly against Trump's shoulder to prevent being strong-armed.
"Trudeau conquers Trump," touted European media stories. One headline in Britain's Telegraph proclaimed Trudeau's handshake was "The Biggest Display of Dominance in the History of Canada."
Frankly, this was an easy category for any Canadian leader to win — mastering a polite, peaceful handshake. It's like Canada winning a world competition in saying "I'm sorry."
Trump's behaviour has called attention to the strange human ritual of grabbing someone's extended limb, then cranking it up and down like a water pump.
The handshake originated in ancient Greece, supposedly as a peaceful gesture to prove both parties weren't carrying knives.
The new greeting gradually won out over other conceivable rival gestures, such as the forehead bang, the chest bounce, the bum bump, the knee knock — and the high five, which took 2,000 years to make a comeback.
But somehow the handshake also became a contest of wills between some boys disguised as men.
As a teenager, I had my palm crushed to a pulp in hand-squeezing competitions on various occasions. Eventually I mastered a firmer grip to use before sports contests and job interviews, as well as against I'll-make-a-man-of-you uncles.
But like most grown-ups I stopped hand-jousting around the same time I stopped having acne.
There are several varieties of well-known handshake: the Bone-crusher, the Yank-and-Pull, the Limp Fish and the Queen-Style Politely-extended Fingertips you're expected to delicately clasp.
There are many cultural alternatives like the Asian bow, the recent fist bump and Quebec's two-cheek embrace. The last ranges from the blown Air Kiss to the Face Graze to the Slobbery Cheek.
Handshakes are powerful symbols that can seal deals, unite foes and signal peace. Germany's Angela Merkel and Trump made news recently by not shaking hands.
But it's hard to remain empty-handed. At a crowded party last month I advised each person I met not to shake my hand, because I had a cold.
As the night wore on and I spurned a host of hands, people started to look at me like I was an unfriendly health freak — for refusing to hand out my germs.
Meanwhile, psychologists are having a field day with theories on the Trump pump. Many say his bullying grip is sending an "America first" message mixed with a "You're fired!" dismissal — and now a "Watch me change your climate, buddy!" threat.
Others point out Trump is a self-confessed "germaphobe" who once said handshakes were "barbaric." So perhaps he's simply overcompensating for his fears - and his aides discretely spray his hand with après-shake lotion.
Scientists recently added a handy study that found people unconsciously smell their hand twice as frequently after a handshake with someone of the same sex, than they did before.
This suggests hand-shaking may be an acceptable human way to sniff out rivals the way other animals do. So keep an eye on he president's paw next time someone shakes it.
World leaders will soon learn to fend off Trump's bullying hand by using the modern tactic of telling Trump "I have a really bad cold." Or using some of our old childhood tricks — like secretly smearing your fingers in Vaseline so his hand slips off.
Or hiding a joy buzzer in your palm that shocks him.
Some world leaders are already finding other ways to handle Trump. The Saudis hung a heavy trumped-up gold medal around his neck, forcing Trump to bow down to receive it.
Pope Francis back by simply not smiling in a photo op, when he often does. Other leaders reportedly swerve out of Trump's way whenever they see him approaching.
Chalk up one more first for Trump (along with endorsing the poisoning of the planet).
He's taken a gesture of peace meant to show you're unarmed and turned it into an arms race.