Jamieson Greer, the U.S. Trade Representative, has become increasingly influential within the Trump administration following the Supreme Court's decision to strike down many of the president's tariffs that were imposed under the International Emergency Economic Powers Act (IEEPA). This ruling, which found that the IEEPA did not grant the president the authority to tax imports, thrust Greer into the spotlight as the main architect of the administration's new tariff strategy. He is now responsible for devising new legal mechanisms to reimpose tariffs and maintain the president's trade agenda.
Greer swiftly responded to the Supreme Court's decision by implementing a 10% tariff on goods from nearly every country for 150 days, utilizing Section 122 of the Trade Act of 1974, which addresses international payments imbalances. Furthermore, he is preparing for long-term tariff initiatives under Section 301 of the same 1974 law, which permits the president to impose tariffs in response to unfair trade practices after an investigation. In March, Greer launched investigations into 96 countries for alleged unfair trade practices, with the aim of concluding these by the summer to potentially allow for the reimposition of flexible tariffs.
His role has expanded significantly as he navigates the complex legal landscape and aims to satisfy President Trump's desire for higher tariffs while also managing international negotiations. Despite the legal setbacks, Greer has maintained that existing trade deals, which were often bolstered by tariff threats, remain intact, with countries expressing willingness to uphold their commitments. He views himself as a pragmatic "technician" who understands the intricacies of trade policy, politics, and the president's objectives, enabling him to implement a durable and flexible tariff regime. This approach is seen by some experts as being on sounder legal footing compared to the previously challenged IEEPA tariffs.
Greer, a former Mormon missionary and military lawyer, served as chief of staff to Robert Lighthizer, Trump's first-term trade representative. Friends note he follows Lighthizer's advice about getting things done quietly. He is seen as a source of stability amidst the administration's often unpredictable nature. His recent busy schedule included flying over 100,000 miles in 2025 and meeting with representatives from numerous countries daily, negotiating to avoid tariffs. He has secured nine reciprocal trade agreements, which trade lawyers praise for being comprehensive and yielding significant concessions for the U.S.
