The Office of the U.S. Trade Representative (USTR) has initiated a massive wave of investigations into the manufacturing practices of 60 trading partners. Launched in mid-March 2026, these Section 301 probes focus on “structural excess capacity” that the U.S. claims is harming its domestic industries. The list of targets is extensive, including major economies such as the European Union, China, Japan, India, and Mexico.
The investigations are a direct response to a Supreme Court ruling that curtailed the President’s ability to impose broad “emergency” tariffs. By shifting to Section 301, the administration is attempting to document specific cases of foreign subsidies and market access barriers. Sectors under the microscope include high-tech fields like robotics and semiconductors, as well as traditional industries like aluminum, cement, and processed foods.
Public hearings on these matters are scheduled for May 2026, where the USTR will gather evidence on whether these foreign policies “burden or restrict” U.S. commerce. If the findings are negative, the administration could implement a new round of permanent tariffs to replace the temporary 10% duties currently in place. This “Plan B” strategy is designed to provide a more stable legal foundation for the President’s trade goals.
The move has particularly high stakes for the North American trade relationship. While Mexico is currently exempted from the temporary Section 122 global tariffs, its inclusion in the overcapacity probe adds a layer of tension to upcoming USMCA review talks. U.S. officials are expected to use the threat of these new findings to push for concessions on rules of origin and supply chain integration.
Global trade professionals are being advised to prioritize supply chain resilience as the “150-day clock” on current temporary tariffs ticks down. With the expiration date of July 24 looming, many organizations are already modeling various scenarios for what might follow. The results of these USTR investigations will likely serve as the primary catalyst for U.S. trade policy heading into the second half of 2026.