The Arms Export Control Act, 22 U.S.C. § 2778, and the rules and regulations promulgated thereunder, 22 C.F.R. § 121-130, prohibit the importation and exportation of arms, ammunition and implements of war without a license from the Department of State. Violations are investigated by the Customs Service.

Unless the unlicensed shipment has no relevance to the foreign relations of the United States (e.g., smuggling small quantities of weapons), prosecution of violations of the Arms Export Control Act should not be undertaken without prior approval of the National Security Division. See JM 9-90.020. However, the United States Attorney is authorized to take whatever action is necessary to prevent the commission of an offense where time does not permit seeking prior authorization. Often an illegal exportation can be circumvented by seizure of the munitions pursuant to the provisions of 22 U.S.C. § 401.