Donald Trump is very proud of his unpredictability. The US president likes to boast that — unlike Barack Obama — he has no intention of signalling his plans to the world.
But, as Mr Trump pursues his first presidential trip overseas, the costs of his unpredictability are becoming clear. Many of America’s allies are in a state of confusion and alarm. And America’s adversaries, in particular China and Russia, are taking advantage of the disarray to advance their own interests.
The problem is that Mr Trump is prone to treat foreign countries like rival businesses — that can be alternately wooed and destabilised — as the US president practises the “art of the deal”. But in diplomacy, unpredictability can be dangerous — particularly when dealing with allies that need to be reassured about the consistency of America’s approach to the world. These nations have built their own global strategies around a belief in the stability and steadfastness of the US.