North Korea’s quest to build a nuclear missile that can hit the US mainland has taken an important step forward. This week, the North Korean regime seems to have staged a successful test of an intercontinental ballistic missile with sufficient range to hit Alaska. The North Koreans have yet to master the difficult technology of fitting a nuclear warhead on to an ICBM, but they are getting dangerously close.

Donald Trump has said that he will never allow North Korea to develop a nuclear weapon that can target America. But, like US presidents before him, Mr Trump is discovering that North Korea is the “land of bad options”.

The Trump administration’s best option now is to widen the range of economic sanctions aimed at North Korea and at foreign companies, particularly in China, that do business with the Pyongyang regime. Over the longer term, the US should keep the door open to diplomatic negotiations into a wider settlement of tensions on the Korean peninsula, talks that could incorporate the nuclear issue.