The invention is a method and system for continuously tracking the movement of cargo in domestic and international shipping from point of departure to point of destination and to prevent hijacking of the same. The system uses one or more wireless electronic seals which can communicate with a central computer system, such as by satellite, providing the current location of the cargo at regular intervals or upon demand. The electronic seals are provided with a unique identification number and are activated upon locking of the seal to the closed cargo container. During shipment, the seal transmits its location to the central computer which compares the location of the shipment to a calculated expected route, notifying the parties to the shipment and government authorities in the event that the cargo is found to deviate from the expected route. The electronic seal is also capable of signaling the central computer when the cargo is opened. If the opening is premature, a second seal hidden within the cargo can be activated to enable tracking of the cargo. The system also provides a consolidated, verifiable record of the shipping history of a shipment which can facilitate government clearance and inspections of potentially dangerous cargo.