International security

Can North Korea's nuclear expansion be stopped?

When President Trump (as he will then be) enters the White House, he will have an item flashing as urgent in his email inbox: North Korea. In the election campaign, he offered to sit down with the country's leader Kim Jong-un over a burger, but that generosity seems less likely now.

Eight years ago, when President Obama moved in, the tone was similarly helpful. Right at the start of his tenure, the new president made a gesture of conciliation to the North Korean leader, not quite an offer of friendship but an indication that nose-to-nose threats need not be the way.

In his inaugural address in 2009, President Obama said he would offer an outstretched hand to those who would "unclench their fists".

A few months later, Kim Jong-un responded with the launch of a substantial, multi-stage rocket and an underground explosion of a nuclear device. Both tests were seen by the United Nations as a defiant contravention of the policy of the non-proliferation of nuclear weapons.