The "Silver Shield Operational End Use Monitoring Act of 2025" establishes the Silver Shield program to enhance accountability for U.S. defense articles and services. This program, to be set up within one year, will monitor whether recipients use these items to inflict civilian harm or violate international humanitarian or human rights law , specifically targeting uses that constitute genocide, crimes against humanity, or grave breaches of the Geneva Conventions. If violations are confirmed, the program mandates a determination of ineligibility for future transfers within 180 days. The program will incorporate data and best practices from existing monitoring initiatives and gather information from diverse sources, including U.S. government personnel, eyewitness accounts, satellite imagery, credible NGO reports, and a new public online portal. It will be coordinated by the Department of State, involving key bureaus and the Department of Defense, and will consult with an external advisory board of experts. The bill amends the Arms Export Control Act and the Foreign Assistance Act of 1961, requiring a written agreement from recipient countries or international organizations, prior to any transfer, pledging not to use U.S. defense articles or services to commit serious violations of international humanitarian or human rights law. These amendments also clarify that promoting the "safety of civilians" is a key purpose of military sales and explicitly state that such violations are not an authorized purpose for U.S. military assistance. The Act authorizes necessary appropriations and requires regular reports to Congress on the program's implementation and investigation status.