US launches Section 301 probes into China, EU, Mexico trade

The United States has launched a new round of trade investigations targeting several major trading partners after the Supreme Court struck down President Donald Trump’s earlier tariff policy. The Office of the United States Trade Representative (USTR) announced that it has initiated investigations under Section 301 of the Trade Act of 1974 into the manufacturing and trade practices of countries including China, the European Union and Mexico.

The move follows a landmark U.S. Supreme Court ruling on February 20, 2026, in which the justices voted 6–3 that the International Emergency Economic Powers Act (IEEPA) does not authorize a president to impose tariffs unilaterally. The decision invalidated tariff programs introduced under the emergency law, including duties targeting imports from China, Canada and Mexico.

Section 301 is one of Washington’s most powerful trade enforcement tools, allowing the government to investigate and respond to unfair or discriminatory trade practices by foreign countries. U.S. Trade Representative Jamieson Greer said the probes will examine issues such as structural excess capacity and industrial policies that could harm U.S. industries.

The investigations reportedly cover around 16 trading partners, including the EU, India, Japan, South Korea, Vietnam, Thailand and Mexico. Depending on the outcome, the process could lead to new tariffs or trade restrictions. Analysts warn the move could revive trade tensions and potentially disrupt global supply chains, similar to the effects seen during earlier U.S.–China tariff disputes.