When Donald Trump reasserted his “America first” mantra on Inauguration Day, the world was put on notice that the new US president would pursue a very different foreign policy than his recent predecessors in the Oval Office.
Yet while some turbulence was expected, the way Mr Trump has treated some of his counterparts since Jan. 20 has left capitals from Tokyo to Berlin perplexed about how to handle a thin-skinned leader who is as willing to antagonise allies as he is to praise Vladimir Putin, the Russian president.
