The warning could not be starker. A sitting Treasury Secretary now says it’s “very unlikely” the Supreme Court will stop Donald Trump from using emergency war powers to hammer America’s closest allies with punishing tariffs—just to force a Greenland deal. European troops are already deploying. Markets are on edge. Allies are furious. 

Donald Trump’s latest tariff threat has turned a long‑running geopolitical obsession into a full‑blown constitutional drama. By tying sweeping tariffs on key European allies to his demand for the “complete and total purchase of Greenland,” he has pushed presidential emergency powers into territory few imagined, even after years of trade wars. European nations, already pledging forces to support Danish sovereignty, now see the move as economic coercion wrapped in national security rhetoric.

Treasury Secretary Scott Bessent’s public confidence that the Supreme Court will not overturn Trump’s use of the International Emergency Economic Powers Act underscores how much is at stake. A ruling that upholds this strategy could cement a precedent where economic warfare becomes a routine tool of presidential leverage, even against allies. A ruling that strikes it down risks market chaos and a direct clash between the branches of government. Between those outcomes lies a fragile transatlantic relationship, Greenland’s uncertain future, and a world watching to see just how far American power can, or should, go.