The trade team under President Donald Trump has initiated sweeping investigations into 16 key U.S. trading partners, setting the stage for a potentially new wave of tariffs following the Supreme Court’s decision last month to invalidate the administration’s previous duties.
On Wednesday, March 11, 2026, U.S. Trade Representative Jamieson Greer announced that his office would investigate China, the European Union, Japan, India, South Korea, Mexico, and ten additional economies for purportedly flooding international markets with excessive manufacturing output. The inquiry might justify fresh import duties on products spanning from steel and semiconductors to processed foods and solar panels ahead of summer.
This move represents the administration’s boldest attempt to resurrect its tariff program following a 6-3 Supreme Court ruling on February 20, 2026, that invalidated President Trump’s International Emergency Economic Powers Act tariffs. Shortly following that judgment, Trump enacted a 10% worldwide tariff utilizing Section 122 of the Trade Act of 1974—a balance-of-payments provision he subsequently elevated to 15%. That charge, nonetheless, lapses after 150 days unless Congress approves an extension, with a probable expiration date around July 24.
The Section 301 inquiries offer an alternative mechanism without legislative time constraints or ceilings on tariff rates. Greer informed reporters that his office intends to complete the investigations before the 150-day period concludes, possibly granting the administration indefinite power to maintain or escalate duties on significant trading partners. Treasury Secretary Scott Bessent recently predicted that by August, U.S. tariffs would revert to the pre-ruling thresholds.
“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 at a press briefing.
A distinct investigation initiated last week is reviewing approximately 60 nations to assess whether foreign governments effectively prohibit imports of products made with forced labor. That inquiry encompasses Canada and the United Kingdom, neither of which appeared on the excess manufacturing capacity list.
The manufacturing inquiry targets economies that Greer claims manufacture considerably more than domestic demand necessitates. Authorities assert that these countries achieve this via subsidies, reduced wages, state-owned enterprises, weak environmental oversight, and currency manipulation. According to administration officials, the outcome undermines U.S. factories and prevents the growth of American manufacturing.
The investigations cover 21 manufacturing sectors. Multiple targeted countries have recently finalized trade agreements with Washington, including Indonesia, which in February achieved a landmark deal eliminating tariffs on over 99% of U.S. exports to that nation.
In contrast to the president’s previous tariff declarations, Section 301 investigations include public comment windows and hearings. The Office of the U.S. Trade Representative will accept written submissions through April 15, with a public hearing on manufacturing overcapacity scheduled to commence May 5. A distinct hearing on forced labor matters is planned for April 28.
The comment period began on March 17, providing interested parties one month to file submissions before the cutoff. Greer has requested formal consultations with all 16 nations identified in the manufacturing probe.
Canada’s exclusion from the manufacturing roster attracted attention, though it is featured in the forced labor investigation. The European Union is present on both rosters, alongside China, Japan, India, South Korea, Vietnam, Mexico, Singapore, Switzerland, Norway, Malaysia, Cambodia, Thailand, Taiwan, Bangladesh, and Indonesia.
Greer indicated that further investigations might be forthcoming. He informed reporters that the administration intends to launch additional Section 301, country-specific inquiries, possibly reviewing rice and seafood markets. The trade representative stated he does not anticipate new Section 232 national security investigations in the upcoming weeks.
The schedule has diplomatic significance. Treasury Secretary Scott Bessent convened with Chinese Vice Premier He Lifeng in Paris on Sunday and Monday, March 15-16, for trade talks, prior to President Trump’s arranged but since delayed state visit to Beijing from March 31 to April 2.
The Trump administration has been informing foreign officials and others that it will not reschedule a summit between the president and Chinese leader Xi Jinping until the war in Iran ends or as soon as possible.
Section 301 power permits the trade representative to impose tariffs, import restrictions, or other trade actions in reaction to unjust foreign practices. The 1974 statute establishes no predetermined limits on duty amounts or timeframe, providing the administration greater flexibility than the balance-of-payments law supporting the existing global tariff.
The investigations launch as the administration scrambles to rebuild its tariff infrastructure following the Supreme Court’s February decision. Whether this fresh legal foundation proves more durable than the previous one will probably be determined by the courts—and by whether Congress approves extending the Section 122 tariffs before they expire in July.