Skip to main content
  • North America
  • Competition Law / International Trade

The U.S. Supreme Court Invalidates Tariffs Imposed Under IEEPA

On 20 February 2026, the U.S. Supreme Court struck down tariffs imposed by President Donald J. Trump under the International Emergency Economic Powers Act (“IEEPA”). In a 6 to 3 ruling, the Supreme Court held that the powers conferred on the President under IEEPA do not extend to the power to impose tariffs. In this newsletter, we analyze the opinion itself, the impact of the ruling on importers’ ability to obtain refunds, the steps already taken by the White House in response, and the effect that the ruling will have on reciprocal tariff agreements between the U.S. and partner countries. Chief Justice Roberts, writing for the majority, found that the term “regulate” as used in IEEPA does not encompass the power to impose tariffs...To read the full article, please see the PDF file

Competition Law / International Trade & North America Newsletter Download PDF [197 KB]

Authors

藤井 康次郎

Kojiro Fujii specializes in the fields of competition law and international trade law. He also covers emerging areas of digital policy/regulations and public policy/regulations, such as those related to sustainability. His expertise in these areas is frequently recognized by international and domestic legal publications. Kojiro also is regularly ranked by Chambers (Band 1 International Trade, Japan and Band 2 TMT, Japan) and Who’s Who Legal (Competition). He achieved the highest ranking in the “International Trade and Economic Security” category of Nikkei’s “Most successful lawyers” (as voted by Japanese companies and peer lawyers) in 2022; he was recognized by Asian Legal Business as one of the Top 15 Technology, Media and Telecommunications Lawyers in Asia in 2023; and he was shortlisted for the FT Innovative Lawyers Awards Asia-Pacific as the Most Innovative Practitioner for his work covering those areas in 2024.

In addition to his career at N&A, he served as the deputy director of the Ministry of Economy, Trade and Industry of Japan, where he handled several important WTO disputes on behalf of the Japanese government. He also worked at a highly reputable international law firm in Washington DC, where he focused on antitrust matters.

平家 正博

Masahiro HEIKE

  • Partner
  • Tokyo

Masahiro Heike specializes in international trade law. From 2016 to 2018, he worked at the Ministry of Economy, Trade and Industry as an in-government lawyer, and handled numerous WTO disputes and trade negotiations and was responsible for the trade policies of other jurisdictions including the United States and China. Currently, he is involved in a wide range of matters including WTO dispute settlement cases, domestic and foreign trade remedy cases (anti-dumping, safeguards), government research related to international trade law, and the handling of tariffs and origin relations.

辰巳 郁

Kaoru TATSUMI

  • NY LLP Partner
  • New York

Mr. Tatsumi mainly advises clients on international and domestic corporate transactions such as mergers, MBOs/LBOs, joint ventures, venture capital investments and other types of M&A transactions, as well as general corporate matters and commercial disputes relating to such corporate transactions; advising major business companies, financial institutions, and private equity funds, both in Japan and overseas.
 
 Mr. Tatsumi is one of only a few lawyers in Japan who has been seconded as an attorney to the Ministry of Justice, and during his tenure there he had a significant role in important governmental activities, such as the amendment of the Companies Act.
 
 Drawing on his significant expertise and deep knowledge, he has authored numerous books and articles in the area of M&A, as well as general corporate law. These publications provide practical solutions to complex legal issues, and bolster Mr. Tatsumi's reputation as a highly respected legal practitioner.