It may well be that Mr Warmbier, a 21-year-old student at the University of Virginia, does not in fact serve that sentence.

The North has a habit of bartering back Western prisoners as part of its bizarre diplomatic game with the US. But there’s no certainty of that, and if it does happen, who knows how long they’ll have to wait before their boy is home?

How did their son come to be in this situation? The answer stirs strong emotions too, some of them less generous than the compassion we should all have for the Warmbiers.

Otto Warmbier was arrested during a five day tour of North Korea. He was travelling with friends on a trip organised by a company called Young Pioneer Tours, which bills itself as “the first company to offer budget tours to the Democratic People’s Republic of Korea”.

Here’s an extract from the firm’s website:

“We are renowned and rated as one of the best tour operators to the DPRK (North Korea) with our unparalleled experience, fun way of doing things, and most importantly, excellent relations in country; this makes us the best choice for your Korea tour.

“As well as seeing the must see sights in Pyongyang and visiting the DMZ, we provide tours to various locations within North Korea.

“So whether you’re looking to compete in the Pyongyang Marathon, experience the spectacular sights of Mt Paektu, ski at the world class Masikryong Ski resort, explore the extreme North East of the country, or visit Rason city – North Korea’s Special Economic Zone, we have itineraries to suit all travellers. “

Which indeed makes North Korea like just another delightful tourist destination, whose unique politics just add a bit of interest for the jaded Western traveller.

Indeed, the firm’s site has numerous photographs of young tourists having a jolly time around North Korea, marvelling at various monuments to the regime and giving (presumably ironic) salutes in the style of its soldiers.