December’s rocket launch and February’s nuclear test defied the world, provoking unanimous UN Security Council resolutions and sanctions. That aroused North Korea’s always fierce rhetoric to a new fever pitch, with the wild talk of pre-emptive nuclear strikes.

This is both worrying, and odd. Kim Jong Un must know that with America bogged down in Afghanistan, the last thing the US wants is another fight in Asia. And South Korea has a new president, Park Geun-hye, who once dined with Kim Jong II and now seeks ‘trustpolitik’ with the North.

So why is the new leader so unyielding. And will he fulfil his menacing threats? Successions are the Achilles’ heel of dictatorships and Kim Jong Un may feel he has to prove to foes abroad and hardliners at home that he is as tough as his father.

But I fear there is more. A year ago North Korea published cartoons showing South Korea’s then president Lee Myung-bak – a hardliner hated by the North – as a rat, being bloodily put to death in various bloodthirsty ways. Similar video games can be found on the internet. Calling Lee a traitor or puppet is one thing, but this was gross, schoolboy smut porn.

Yet I detect a readiness for battle. The rest of us must make do with fantasy computer games, but Kim Jong Un commands real soldiers, and real nukes. Is he having fun putting the wind up the world, or does he have deadly intent?