The Northern Ireland (Emergency Provision) Act of 1978 and the Offenses Against the State Acts, 1939-1985, are analyzed, along with earlier British counterterrorism legislation and current worldwide measures. This study concentrates on the history and structure of the 1984 act. Proscription, exclusion orders, a list of special offenses, the powers of arrest and search granted, and port controls are described. The overall effects of the acts are judged by statistics and examples of enforcement. Appendixes contain an 88-item bibliography, summaries of legislative proposals; reprint of the 1984 act; and table of cases, statutes, and subordinate legislation. Chapter notes and index.