The Department of State Directorate of Defense Trade Controls (DDTC) interprets and enforces ITAR. Its goal is to safeguard U.S. national security and further U.S. foreign policy objectives. The related Export Administration Regulations (Code of Federal Regulations Title 15 chapter VII, subchapter C) are enforced and interpreted by the Bureau of Industry and Security in the Commerce Department. The Department of Defense is also involved in the review and approval process. Physical enforcement of import and export laws at border crossings is performed by Customs and Border Protection, an agency of the Department of Homeland Security.
For practical purposes, ITAR regulations dictate that information and material pertaining to defense and military related technologies (for items listed on the U.S. Munitions List) may only be shared with U.S. Persons unless authorization from the Department of State is received or a special exemption is used. U.S. Persons (including organizations) can face heavy fines if they have, without authorization or the use of an exemption, provided foreign (non-US) persons with access to ITAR-protected defense articles, services or technical data.