Export Administration Act of 1979
The Export Administration Act (EAA) of 1979 (P.L. 96-72) provided legal authority to the President to control U.S. exports for reasons of national security, foreign policy, and/or short supply. However, the 1990 farm bill (P.L. 101-624) provided for contract sanctity by prohibiting the President from restricting the export of any agricultural commodity already under contract for delivery within 270 days from the date an embargo is imposed under the EAA, except during national emergency or war. With the expiration of EAA in 1994, the President declared a national emergency and exercised authority under the International Emergency Economic Powers Act (P.L. 95-223; 50 U.S.C. 1701 et seq.) to continue the EAA export control regulations then in effect by issuing Executive Order 12924 on August 19, 1994. Presidents since then have each year extended these regulations by Presidential Notice.
Federal Law/Regulation Forbidding Anti-Israel Boycotts
"Those laws discourage, and in some circumstances, prohibit U.S. companies from furthering or supporting the boycott of Israel sponsored by the Arab League, and certain Muslim countries, including complying with certain requests for information designed to verify compliance with the boycott. " 
- This article incorporates public domain material from the Congressional Research Service document "Report for Congress: Agriculture: A Glossary of Terms, Programs, and Laws, 2005 Edition" by Jasper Womach.