U.S. President Donald Trump announced Saturday that he is raising the global tariff rate from 10% to 15%, effective immediately, following a Supreme Court ruling that struck down his authority to levy tariffs under the International Emergency Economic Powers Act. The increase builds on a 10% global rate Trump introduced Friday using alternative legal statutes, specifically the Trade Expansion Act of 1962 and the Trade Act of 1974.

Trump posted on Truth Social that he was raising the rate “to the fully allowed, and legally tested, 15% level,” citing what he described as decades of unfair trade…