Darth Vader isn’t known as a symbol of international diplomacy.
But this week, he made a brief appearance in the world of global negotiations with a cameo on Justin Trudeau’s feet.
The Canadian prime minister started a week-long trip to India wearing a pair of Star Wars-themed socks – a choice that it is rumoured could be an attempt to charm the country’s President, Narenda Modi, who is reportedly a fan of the movie franchise.
And it is not the first time Mr Trudeau has played diplomacy and provoked excitement with a flash of ankle.
Yellow rubber ducks, Chewbacca and R2D2, a skull and crossbones and maple leaves are all united by the common thread of his footwear.
Perhaps his most memorable sartorial selection came during last year’s Toronto Pride, which coincided with Eid – prompting Mr Trudeau to choose rainbow socks emblazoned with the phrase Eid Mubarak, bought from a local Halal sock producer.
He also drew laughs from world leaders at a recent meeting in Belgium, with a pair of socks bearing the logo of intergovernmental military alliance NATO.
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The idiosyncrasy has been seized on by people looking to charm the prime minister.
At the World Economic Forum Summit in Davos earlier this year, Coca-Cola boss James Quincey handed Mr Trudeau a pair of socks emblazoned with his drinks company’s logo.
In November, Taoiseach Leo Varadkar proudly revealed a pair of maple leaf socks during a meeting with the Canadian leader.
Mr Trudeau’s choices here could be strategic: according to a 2014 Harvard Business Review study, people who appear to adopt non-conforming behaviours tend to be held in higher regard than their counterparts.
The study, titled the Red Sneaker Effect, says items such as “crazy socks” can act as a “particular form of conspicuous consumption” that prompts people to view others more favourably – as long as they are seen in be in control and intentionally displaying non-conforming behaviour, that is.
But not everyone has been charmed by the footwear preferences of young and studiedly quirky world leaders.
New Sinn Fein leader Mary Lou McDonald recently dismissed Mr Varadkar’s socks in cutting terms.
“Leo’s kind of smarmy,” she said. “You’ll have seen him in Number 10 talking about Love Actually and donning various pairs of socks.”
Other commentators think a preoccupation with prime ministerial footwear detracts from more important matters.
They suggest the show of colourful clothing casts Mr Trudeau as a likeable, moral leader and stops people asking more difficult questions about his approach and record.
History has so far suggested a weak correlation between sock-based non-conformity and political allegiances.
One of the last politicians to attract attention for an interest in printed socks was George HW Bush, who in 2013 wore, for seemingly no good reason, a pair of socks printed with his own face.
On several trips to visit the former president, Bill Clinton made sure to take along novelty socks and tweet about his choice of gift.
UK Labour Party leader Jeremy Corbyn, however, provoked consternation when it was revealed he wore open-toed sandals with socks – a faux pas which prompted some to doubt his suitability as a leader.
Whether you’re a fan or not, it seems unlikely that sock selection will disappear from the headlines any time soon.