Don’t just do it. Mean it.

It’s been quite a week for Nike.

On Monday, they launched a bold new advertising campaign, fronted by Colin Kaepernick (the star San Francisco quarterback who caused a furore by kneeling, rather than standing, during the national anthem, to protest in support of the ‘black lives matter’ movement).

Clearly, this was always going to be controversial. Conservative Americans, led vocally by their President, have railed against the protest on the grounds that it disrespects the anthem and the country.

By Tuesday lunchtime, the backlash was in full swing, with indignant mid-westerners sharing videos of mutilated Nike products on social media, accompanied by the hashtag #JustBurnIt.

All of which must have had Nike’s brand folks rubbing their hands in glee. After all, what better way to make your product relevant to teenagers than by having chubby, middle-aged rednecks get angry about it? (Not to mention the billions of dollars of free global publicity – they probably only had to run the ad once).

But let’s hope that, before they started all this hoopla, they took a deep breath and re-read the second line of the advert: ‘even if it means sacrificing everything’.

Because it’s easy to believe in something. But it’s a lot less easy to keep believing in it when the consequences escalate.

I’m not talking about a few good ol’ boys cutting Nike swooshes out of their socks. I’m talking about shop windows being smashed. About people being attacked because they work for Nike. About retailers being too scared to sell Nike products – and shoppers being too scared to buy them. About sales falling off a cliff because they misjudged the reaction.

What happens then? Do Nike’s senior leaders apologise and backtrack, in a bid to stop haemorrhaging money? If they do, the brand’s credibility will be shredded for a generation.

I hope that doesn’t happen. I admire Kaepernick – and Nike for having the guts to celebrate him. And I’m confident the backlash will be much less extreme than I’ve suggested above. But, if it isn’t, I hope they hold their nerve and tough it out.

As the advertising guru Bill Bernbach once put it, ‘a principle isn’t a principle until it costs you money.’

We may all be about to find out how authentic Nike’s principles are.