US President Donald Trump’s imposition of a 25 per cent tariff on steel and aluminium weighed on global markets. According to the US President’s proclamation, on January 19, 2018, the US Secretary of Commerce (Secretary) conveyed a report into the effect of imports of aluminium on the national security of the United States (US) [under section 232 of the Trade Expansion Act of 1962, as amended (19 U.S.C. 1862) (section 232)], which highlights that aluminium is being imported into the US in such quantities and under such circumstances as to threaten to impair the national security of the United States.