In the first week of November, the US Supreme Court is set to deliver a verdict that will decide the fate of President Donald Trump’s most powerful economic weapon: tariffs. As the court prepares to hear this landmark case, the Trump administration is paradoxically proposing its most extreme use of that weapon yet—a 100% tariff on India and China.
The legal challenge argues that the president has “exceed[ed] any authority granted” to him by unilaterally imposing tariffs, a position upheld by multiple lower courts. A final ruling against the administration would not only dismantle existing trade barriers but would also force a massive refund of tens of billions of dollars, a prospect the Treasury Secretary has called “terrible.”
Despite this existential threat to his policy, Trump is moving forward aggressively. His new proposal, made to the European Union, seeks to use the contested tariff authority to pressure Russia’s allies and end the war in Ukraine. The US has told the EU it is “ready to go,” but only if they join the effort.
This creates a high-stakes timeline. The administration is trying to build an international coalition for a new tariff war even as its legal right to wage one is about to be decided. The November verdict will therefore not only have vast domestic financial implications but will also determine the future of Trump’s tariff-driven foreign policy.