Paul Rosen serves as the assistant secretary of the Treasury for investment security. Nominated by the president and confirmed with bipartisan support by the United States Senate on May 23, 2022, Paul leads all operations and activities of the Committee on Foreign Investment in the United States (CFIUS), the interagency committee authorized by Congress to review certain foreign investment into US businesses for national security risks. He oversees the review of hundreds of transaction filings each year, often amounting to hundreds of billions of dollars in investment activity, and is responsible for managing the committee's recommendations to the president to suspend or prohibit transactions that threaten to impair the national security of the United States. He also guides the committee's policy and international-relations activities as well as the monitoring, compliance, and enforcement of national-security agreements executed to mitigate national-security risk.

Paul has more than 15 years of experience in national and homeland security and law enforcement matters. Prior to joining Treasury, he served as a partner at an international law firm, where he led the firm's national-security practice and counseled on cybersecurity, privacy, and government investigations matters. Before joining private practice, Paul served in public service for over a decade in senior roles in the federal government, including as chief of staff at the Department of Homeland Security and in various roles at the Department of Justice, including as a federal prosecutor in the Criminal Fraud Section, where he investigated and prosecuted financial crimes. For this work, Paul was recognized by the Council of the Inspectors General on Integrity and Efficiency with the Investigative Award of Excellence.

Paul started his legal career as counsel on the Senate Judiciary Committee after clerking in the Central District of California for US District Judge Gary Allen Feess (ret.). He received his JD from the University of Southern California, where he graduated Order of the Coif, and his bachelor's degree summa cum laude from the University of Colorado.