The Trump administration has initiated Section 301 investigations into South Korea, China, Japan, the European Union, and 13 other economies over unfair practices tied to structural excess capacity in manufacturing. The probes follow a Supreme Court ruling invalidating prior tariffs and aim to establish permanent measures to protect U.S. jobs. South Korea vows active consultations to safeguard its interests.
On March 12, 2026, U.S. Trade Representative Jamieson Greer announced a Section 301 investigation under the 1974 Trade Act targeting 16 economies: South Korea, China, India, Japan, the European Union, Singapore, Switzerland, Norway, Indonesia, Malaysia, Cambodia, Thailand, Vietnam, Taiwan, Bangladesh, and Mexico. The probe focuses on unfair practices such as subsidies, suppressed wages, state-owned enterprise activities, market barriers, weak labor/environmental standards, subsidized lending, financial repression, and currency manipulation contributing to excess manufacturing capacity.
The move comes after the U.S. Supreme Court last month struck down country-specific reciprocal tariffs imposed under the International Emergency Economic Powers Act (IEEPA). Greer emphasized, "The policy remains the same. The tools may change depending upon the vagaries of courts." Following the ruling, President Trump imposed a temporary 10% global tariff under Section 122, set to rise to 15% and expire after 150 days.
For South Korea, the USTR highlighted a global goods trade surplus of $52 billion in 2024 (up from a $10 billion deficit in 2023) and a $56 billion bilateral surplus with the U.S. in 2024, holding at $49 billion through June 2025. Key sectors include electronics, autos, machinery, steel, and ships; the Korean government has acknowledged excess capacity in petrochemicals. Current tariffs include 10-15% on globals, 15% on autos, and 50% on steel/aluminum under Section 232.
South Korea's government pledged active consultations. Trade Minister Yeo Han-koo stated, "We will closely consult with the U.S. so as not to harm the balance of profits from the Korea-U.S. tariff agreement," attributing surpluses to Korean investments in U.S. manufacturing. A Cheong Wa Dae official added that Seoul seeks to avoid less favorable treatment than other nations. The probe is unrelated to South Korea's ongoing investigation into a Coupang data leak affecting 33 million users, which the U.S. raised but Korea defended as due process.
The process is accelerated and public: docket opens around March 18, comments by April 15, hearings around May 5. Potential remedies include tariffs, service fees, or negotiations. A parallel Section 301 probe on forced labor bans is forthcoming. The administration views global trade as tilted against U.S. producers and plans further investigations into pharma pricing, digital taxes, tech discrimination, and ocean pollution, plus Commerce probes on robotics and wind turbines.
