Defense-related articles and services on the United States Munitions List (USML) are covered by the regulations, which implement the provisions of the Arms Export Control Act (AECA), and are described in Title 22 (Foreign Relations), Chapter I (Department of State), Subchapter M of the Code of Federal Regulations. The Department of State Directorate of Defense Trade Controls (DDTC) interprets and enforces ITAR. 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 the ITAR; and all import and export laws of the United States is performed by Homeland Security Investigations Special Agents (formerly U.S. Customs) under Immigration and Customs Enforcement, an agency of the Department of Homeland Security. Additionally, Customs and Border Protection Officers, also under the Department of Homeland Security, inspect imports and exports at U.S. Border Crossings and International Airports and enforce import and export regulations.
For practical purposes, ITAR regulations dictate that information and material pertaining to defense and military related technologies (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 persons with access to ITAR-protected defense articles, services or technical data.
The U.S. Munitions List changes over time. Until 1996–1997, ITAR classified strong cryptography as arms and prohibited their export from the U.S. Another change occurred as a result of Space Systems/Loral's conduct after the February 1996 failed launch of the Intelsat 708 satellite. The Department of State charged Space Systems/Loral with violating the Arms Export Control Act and the ITAR. As a result, technology pertaining to satellites and launch vehicles became more carefully protected.
ITAR does not apply to information related to general scientific, mathematical or engineering principles that are commonly taught in schools and colleges or information that is in the public domain.:§ 120.10(5):§ 120.11 Nor does it apply to general marketing information or basic system descriptions.:§ 120.10(5) Broad interpretations of these exceptions have faced several legal challenges. For example, college professors have been prosecuted for breaches of the AECA as a result of access to USML items by foreign graduate students and companies have been penalized for alleged breaches of the AECA for failing to properly remove USML items from material used to market defense articles. The U.S. Government has also taken action (albeit unsuccessfully) for the export of technical data that was allegedly already publicly available on the Internet.
ITAR applies to items identified under the Invention Secrecy Act.