Spare a thought for the parents of Otto Warmbier today. Their child is in the hands of the North Korean regime, sentenced to 15 years of hard labour for “crimes against the state”.

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?

And until he is, Fred and Cindy Warmbier will know neither peace nor happiness.

"Taking a tourist trip there means spectating on the murder and abuse of your fellow human beings, and putting hard currency into the hands of the people responsible for those crimes."

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”.