Leading article: Kim Jong-un may yet confound the pessimists

When Kim Jong-un took over as "supreme leader" in December, few North Korea-watchers predicted much good would come of it. His power is too fragile, commentators cautioned; he couldn't change anything even if he wanted to. Neither can a country as closed and as beleaguered as North Korea afford to look like it is giving in to outside pressure.

Then, within days, Mr Kim's administration warned "foolish politicians" elsewhere in the world "not to expect any changes". Hardly a promising start.

Even more reason, then, to welcome the deal under which Pyongyang will freeze its nuclear weapons programme in return for 240,000 tonnes of US food aid. It would be well not to be too trusting. But the move is still, as the White House says, "a positive first step". More importantly, it suggests Mr Kim may be more than a paper tiger after all.