President Donald Trump’s trade team has opened broad investigations into 16 principal U.S. trading partners, potentially paving the way for a fresh round of tariffs after the Supreme Court overturned the administration’s earlier duties last month.
U.S. Trade Representative Jamieson Greer said on Wednesday, March 11, 2026, that his office will probe China, the European Union, Japan, India, South Korea, Mexico, and ten other economies for allegedly inundating global markets with surplus manufacturing capacity. The inquiry could justify new import taxes on products ranging from steel and semiconductors to processed foods and solar panels before summer.
The action is the administration’s strongest move yet to revive its tariff strategy after a 6-3 Supreme Court decision on February 20, 2026, struck down President Trump’s duties under the International Emergency Economic Powers Act. Days after that ruling, Trump implemented a 10% global tariff under Section 122 of the Trade Act of 1974—later raised to 15%—but that measure can only last 150 days unless Congress votes to extend it, with the deadline around July 24.
Section 301 probes provide a route around those time limits and impose no explicit caps on tariff levels. Greer told reporters his office aims to finish the investigations before the 150-day window ends, which could give the administration open-ended authority to keep or increase duties on major trade partners. Treasury Secretary Scott Bessent recently forecasted that by August, U.S. tariffs would revert to pre–Supreme Court ruling levels.
“Our view is that key trading partners have developed production capacity that is really untethered from the market incentives of domestic and global demand,” Greer said during a press briefing.
A second inquiry, launched Thursday, covers about 60 countries and examines whether foreign governments effectively prohibit imports of goods produced with forced labor. That investigation includes Canada and the United Kingdom, neither of which appeared on the excess manufacturing capacity list.
The manufacturing probe focuses on economies Greer alleges produce far more than their domestic markets consume, achieved through subsidies, low wages, state-owned enterprises, lax environmental rules, and currency manipulation. According to administration officials, this displaces U.S. factories and blocks the growth of American manufacturing.
The investigations span 20 manufacturing sectors, including aluminum, automobiles, batteries, cement, chemicals, electronics, energy goods, glass, machine tools, machinery, paper, plastics, processed foods, robotics, satellites, semiconductors, ships, solar modules, steel, and transportation equipment. Several targeted nations recently finalized trade deals with Washington—Indonesia, for example, struck a landmark agreement in February, removing tariffs on more than 99% of U.S. exports to that market.
Unlike the president’s earlier tariff proclamations, Section 301 investigations include public comment periods and hearings. The Office of the U.S. Trade Representative will accept written comments through April 15, with a public hearing on manufacturing excess capacity set to start May 5. A separate hearing on forced labor issues is scheduled for April 28.
The comment docket opened on March 17, giving stakeholders exactly one month to submit input before the deadline. Greer has sought formal consultations with all 16 governments named in the manufacturing probe.
Canada’s omission from the manufacturing list drew notice, though it is included in the forced labor inquiry. The European Union appears on both lists, as do China, Japan, India, South Korea, Vietnam, Mexico, Singapore, Switzerland, Norway, Malaysia, Cambodia, Thailand, Taiwan, Bangladesh, and Indonesia.
Greer said more probes could follow, noting the administration expects to open additional Section 301 country-specific investigations, possibly looking at rice and seafood markets. He added he does not expect new Section 232 national security investigations in the immediate weeks ahead.
Bessent and Greer carried the new investigations as a fresh irritant into the Paris trade talks with Chinese Vice Premier He Lifeng on March 15-16, where the agenda included rare earth mineral flows, agricultural purchase commitments, and U.S. technology export controls. After the Paris meetings concluded, Bessent described the two days as “very good” but acknowledged that Trump’s planned state visit to Beijing from March 31 to April 2 could be delayed — not because of China’s refusal to help police the Strait of Hormuz, but because Trump may choose to remain in Washington to coordinate the Iran war effort.
Section 301 authority allows the trade representative to impose tariffs, import limits, or other trade actions in response to unfair foreign practices. The 1974 law does not set predetermined caps on duty rates or durations, giving the administration far more flexibility than the balance-of-payments authority underpinning the current global tariff.
The investigations launch as the administration works to rebuild its tariff framework after the Supreme Court’s February ruling. Whether this new legal approach proves more resilient than the previous one will likely be decided by the courts—and by whether Congress extends the Section 122 tariffs before they lapse in July.
China denounced the Section 301 probes as “extremely unilateral, arbitrary and discriminatory” and reserved the right to take countermeasures, while trade experts warned the administration was squandering an opportunity to build a coalition against Chinese overcapacity by sweeping in over a dozen allied economies.
Legal experts are already questioning whether the Section 301 approach will survive its own court challenge, arguing that using the authority to broadly reimpose reciprocal-style tariffs across most of U.S. trade will raise the same constitutional questions that caused the Supreme Court to strike down the IEEPA duties — since both approaches effectively amount to a sweeping, non-negotiated tariff wall rather than a targeted response to specific unfair practices.
