Question: John le Carré worked for a UK service bound by what?

full_context: Document 1: General Intelligence Directorate (Egypt): The General Intelligence Directorate (Arabic: جهاز المخابرات العامة‎ ‎ "Gihaz El Mukhabarat El ‘Amma" ), often referred to as the Mukhabarat (Egyptian Arabic: المخابرات‎ ‎ "El Mukhabarat" ) is an Egyptian intelligence agency responsible for providing national security intelligence, both domestically and transnationally, with a counter-terrorism focus. The GID is part of the Egyptian intelligence community, together with the Office of Military Intelligence Services and Reconnaissance (Egyptian Arabic: إدارة المخابرات الحربية والاستطلاع‎ ‎ "Idarat El Mukhabarat El Ḥarbiya Wel Istitlaʾ" ) and National Security Agency (Egyptian Arabic: قطاع الأمن الوطني‎ ‎ "Ketaʿ El Amn El Watani" ).
Document 2: James Bond: The James Bond series focuses on a fictional British Secret Service agent created in 1953 by writer Ian Fleming, who featured him in twelve novels and two short-story collections. Since Fleming's death in 1964, eight other authors have written authorised Bond novels or novelizations: Kingsley Amis, Christopher Wood, John Gardner, Raymond Benson, Sebastian Faulks, Jeffery Deaver, William Boyd and Anthony Horowitz. The latest novel is "Trigger Mortis" by Anthony Horowitz, published in September 2015. Additionally Charlie Higson wrote a series on a young James Bond, and Kate Westbrook wrote three novels based on the diaries of a recurring series character, Moneypenny.
Document 3: Security agency: A security agency is a governmental organization which conducts intelligence activities for the internal security of a nation. They are the domestic cousins of foreign intelligence agencies, and typically conduct counterintelligence to thwart other countries' foreign intelligence efforts. For example, the United States Federal Bureau of Investigation (FBI) is the internal intelligence, security and law enforcement agency, while the Central Intelligence Agency (CIA) is an external intelligence service, which deals primarily with intelligence collection overseas. A similar relationship exists in Britain between MI5 and MI6.
Document 4: George Smiley: George Smiley OBE is a fictional character created by John le Carré. Smiley is a career intelligence officer with "The Circus", the British overseas intelligence agency. He is a central character in the novels "Call for the Dead", "A Murder of Quality", "Tinker Tailor Soldier Spy", "The Honourable Schoolboy", and "Smiley's People", and a supporting character in "The Spy Who Came in from the Cold", "The Looking Glass War", "The Secret Pilgrim" and "A Legacy of Spies".
Document 5: John le Carré: David John Moore Cornwell (born 19 October 1931), known by the pseudonym John le Carré ( ), is a British author of espionage novels. During the 1950s and the 1960s, he worked for both the Security Service and the Secret Intelligence Service, and began writing novels under his pen name. His third novel, "The Spy Who Came in from the Cold" (1963), became an international best-seller and remains one of his best-known works. Following the success of this novel, he left MI6 to become a full-time author.
Document 6: Secret service: A secret service is a government agency, intelligence agency, or the activities of a government agency, concerned with the gathering of intelligence data. The tasks and powers of a secret service can vary greatly from one country to another. For instance, a country may establish a secret service which has some policing powers (such as surveillance) but not others. The powers and duties of a government organization may be partly secret and partly not. The organization may be said to operate openly at home and secretly abroad, or vice versa. Secret police and intelligence agencies can usually be considered secret services.
Document 7: List of James Bond novels and short stories: The James Bond literary franchise is a series of novels and short stories, first published in 1953 by Ian Fleming, a British author, journalist, and former naval intelligence officer. James Bond, often referred to by his code name, 007, is a British Secret Service agent; the character was created by journalist and author Ian Fleming, and first appeared in his 1953 novel "Casino Royale"; the books are set in a contemporary period, between May 1951 and February 1964. Fleming went on to write a total of twelve novels and two collections of short stories, all written at his Jamaican home Goldeneye and published annually. Two of his books were published after his death in 1964.
Document 8: Call for the Dead: Call for the Dead is John le Carré's first novel, published in 1961. It introduces George Smiley, the most famous of le Carré's recurring characters, in a story about East German spies inside Great Britain. It also introduces a fictional version of British Intelligence, called "the Circus" because of its location in Cambridge Circus, that is apparently based on MI6 and that recurs throughout le Carré's spy novels.
Document 9: British intelligence agencies: The Government of the United Kingdom maintains intelligence agencies within several different government departments. The agencies are responsible for collecting and producing foreign and domestic intelligence, providing military intelligence, performing espionage and counter-espionage. Their intelligence assessments contribute to the conduct of the foreign relations of the United Kingdom, maintaining the national security of the United Kingdom, military planning and law enforcement in the United Kingdom. The three main agencies are the Secret Intelligence Service (MI6), the Security Service (MI5), and the Government Communications Headquarters (GCHQ).
Document 10: Government Communications Headquarters: The Government Communications Headquarters (GCHQ) is an intelligence and security organisation responsible for providing signals intelligence (SIGINT) and information assurance to the government and armed forces of the United Kingdom. Based in "The Doughnut" in the suburbs of Cheltenham, GCHQ is the responsibility of the country's Secretary of State for Foreign and Commonwealth Affairs, but it is not a part of the Foreign Office and its director ranks as a Permanent Secretary.
Document 11: Tinker Tailor Soldier Spy: Tinker Tailor Soldier Spy is a 1974 spy novel by British author John le Carré. It follows the endeavors of taciturn, aging spymaster George Smiley to uncover a Soviet mole in the British Secret Intelligence Service. Since the time of its publication, the novel has received critical acclaim for its complex social commentary and lack of sensationalism, and remains a staple of the spy fiction genre.
Document 12: MI5: The Security Service, also MI5 (Military Intelligence, Section 5), is the United Kingdom's domestic counter-intelligence and security agency and is part of its intelligence machinery alongside the Secret Intelligence Service (MI6), Government Communications Headquarters (GCHQ) and Defence Intelligence (DI). MI5 is directed by the Joint Intelligence Committee (JIC), and the service is bound by the Security Service Act 1989. The service is directed to protect British parliamentary democracy and economic interests, and counter terrorism and espionage within the UK.
Document 13: MI5(g): The MI5(g), or the MI5 G section, was a branch of MI5 that was formed during World War I to address the wartime espionage operation by the Indian revolutionary movement in Europe. The department arose by renaming the MO5(g), which was renamed MI5(g) in 1916. The MI5 itself, working under Vernon Kell, had a number of India experts at the beginning of the war. In September 1916, a special section, the MI5(d), section was formed to operate counter-espionage networks throughout the British Empire. Another subsection, the MI5(b), was formed in January 1917 to deal specifically with Indians and "other oriental races". The MI5(g) had 27 officers in its staff, eight of whom had served in India before the war. Among them were ex-Indian civil servants including Robert Nathan and H. L. Stephenson. The main emphasis of this counter-espionage network was to prevent the subversion of Indian troops in the European theatre. The organisation, especially under Nathan, worked closely with the Special Branch of the Scotland Yard in Britain and with the Indian Political Intelligence Office headed by John Wallinger, which operated a network of spies in neutral Switzerland which a number of the Indian revolutionaries and members of the Berlin Committee used as a base.
Document 14: Control (fictional character): Control is a fictional character created by John le Carré. Control is an intelligence officer who acts as the head of "the Circus", the British overseas intelligence agency. He is a character in the novels "The Spy Who Came in from the Cold", "The Looking Glass War", and "Tinker Tailor Soldier Spy", and is referred to in several others, usually by association with le Carré's recurring protagonist George Smiley, who has served as Control's right-hand man.
Document 15: Cold (novel): Cold, first published in 1996, was the sixteenth and final novel by John Gardner featuring Ian Fleming's secret agent, James Bond (including Gardner's novelizations of "Licence to Kill" and "GoldenEye"). Carrying the Glidrose Publications copyright, it was first published in the United Kingdom by Hodder & Stoughton and in the United States by Putnam.
ground_truth: Security Service Act 1989