US President Donald Trump issues quite a few executive orders. So many, in fact, that one could be forgiven for not keeping up with them all.But amid the rapid-fire policy changes that have come to characterise his administration, one arrived last month that could have drastic implications for the world’s drone market – and China’s role in it.The order, signed June 6, requires government agencies to prioritise using home-grown unmanned aircraft systems (UAS) “to the maximum extent permitted by...