President Trump’s Section 232 directive for aluminium opens up a Pandora’s box of trade conflict and legal confusion. At the time of writing, Canada, Mexico and Australia were exempt from the duties, due to become effective on 23 March. Other countries may well be added before then. In this Insight we assess the real impact on the wider US aluminium industry and investigate the displacement and redirection of primary aluminium flows at a global level. The results suggest that the policy may end up doing more harm than good for the US aluminium sector.