<h1>Threatened 10% US tariff on eight European states over Greenland imposing extraterritorial trade effects, prompting legal risk</h1> The instrument concerns threatened imposition of a 10% tariff by the US President on eight European states for actions regarding Greenland; this constitutes an asserted extraterritorial tariff measure and, if applied, would functionally subject those states (and potentially the EU single market) to unilateral US trade restrictions, producing immediate economic effects on cross-border trade. A secondary legal issue is uncertainty as to statutory authority: implementation would rely on asserted emergency economic powers under US law currently the subject of pending Supreme Court litigation, creating legal vulnerability and procedural risk to enforcement. The measure also raises implications for NATO territorial-security coordination as an alternative diplomatic remedy.