British military operations in Northern Ireland have been reduced due to the increased use of electronic surveillance and the expanded use of the police to conduct investigations and arrests. The British Royal Marines have a crack commando unit known as the SBS. This unit is prepared to mount various counter-terrorist operations and defends Britain's North Sea oil rigs from terrorist attack. The Irish army and its police force have stepped up efforts to curb IRA activities across the border. The British have a system of informant development and control as well as emergency laws and court procedures for addressing the terrorist threat. The British prefer, however, to use the regular court system for dealing with terrorist defendants. Allegiance to the traditional court system has prevented emergency measures from being used arbitrarily. An arrested terrorist has an opportunity to appear before a tribunal presided over by a judge and to be represented by counsel. The effectiveness of the British antiterrorism tactics is manifested in a reduction in guerrilla strength, the incarceration of 1,200 terrorists, and IRA reluctance to engage in a sustained campaign in major cities. 46 notes.