US HB4502

Establishes the "Silver Shield" program within 1 year to monitor whether U.S. defense articles and services sold or transferred abroad are used to inflict civilian harm or violate international humanitarian or human rights law

Requires 180-day determinations on allegations that U.S. weapons were used to commit genocide, crimes against humanity, grave breaches of the Geneva Conventions, or other serious violations, with ineligibility consequences for recipients

Amends the Arms Export Control Act and Foreign Assistance Act to require recipient countries to sign written agreements not to use U.S. defense articles to violate international law, and adds civilian safety as an eligibility criterion for arms transfers

Creates an external advisory board of academic and NGO experts and authorizes multiple information sources for monitoring, including satellite imagery, NGO reports, site visits, and a public online portal

Mandates annual reports to Congress on program implementation, costs, staffing, and the number and status of ongoing investigations into potential violations