THE AUTHOR FOCUSES MAINLY ON THE AGENCIES' EFFORTS TO COUNTER AND CONTAIN POLITICAL MOVEMENTS IN GREAT BRITAIN. THE TEXT DRAWS TOGETHER DOCUMENTARY SOURCES TO PROVIDE BOTH AN HISTORICAL AND CONTEMPORARY PERSPECTIVE ON THE FORCES OF THE STATE. AMONG THE SPECIFIC AREAS EXAMINED ARE THE OFFICIAL SECRETS ACTS, INCITEMENT AND SEDITION, TELEPHONE-TAPPING AND MAIL-OPENING, THE POLITICAL ROLE OF THE UNIFORMED POLICE, THE SPECIAL BRANCH, MILITARY INTELLIGENCE, THE DEFENSE INTELLIGENCE STAFF, THE PRIVATE SECURITY INDUSTRY, AND THE STATE'S COUNTERREVOLUTIONARY PREPARATIONS SUCH AS THE NATIONAL SECURITY PLAN. SPECIAL ATTENTION IF GIVEN TO THE TECHNOLOGY USED TO COMBAT INTERNAL SUBVERSION. (AUTHOR ABSTRACT MODIFIED)