MI5

The Security Service, commonly known as MI5 (Military Intelligence, Section 5), is the United Kingdom's internal counter-intelligence and security agency and is part of its core intelligence machinery alongside the Secret Intelligence Service (SIS or MI6) focused on foreign threats, Government Communications Headquarters (GCHQ) and Defence Intelligence (DI). All come under the direction of the Joint Intelligence Committee (JIC). The service has a statutory basis in the Security Service Act 1989 and the Intelligence Services Act 1994. Its remit includes the protection of British parliamentary democracy and economic interests, counter-terrorism and counter-espionage within the UK. Although mainly concerned with internal security, it does have an overseas role in support of its mission.

Within the civil service community the service is colloquially known as Box 500 (after its official wartime address of PO Box 500; its current address is PO Box 3255, London SW1P 1AE).

The service has had a national headquarters at Thames House on Millbank in London since 1995, drawing together personnel from a number of locations into a single HQ facility. Thames House is shared with the Northern Ireland Office and is also home to the Joint Terrorism Analysis Centre, a subordinate organisation to the Security Service. The service has offices across the United Kingdom including an HQ in Northern Ireland.

Details of the northern operations centre in Greater Manchester were revealed by the firm who built it. Plans to open the northern operations centre were reported by The Manchester Evening News in February 2005, and plans to open a permanent Scottish office in Glasgow were reported by The Scotsman in January of that year.

Command, control and organisation
The Security Service comes under the authority of the Home Secretary within the Cabinet. The service is headed by a Director General at the grade of a Permanent Secretary of the British Civil Service who is directly supported by an internal security organisation, secretariat, legal advisory branch and information services branch. The Deputy DG is responsible for the operational activity of the service, being responsible for four branches; international counter-terrorism, National Security Advice Centre (counter proliferation and counter espionage), Irish and domestic counter-terrorism and technical and surveillance operations.

The service is directed by the Joint Intelligence Committee for intelligence operational priorities and liaises with the SIS, GCHQ, DIS and a number of other bodies within the British government and industrial base. The service is overseen by the Intelligence and Security Committee of Members of Parliament, directly appointed by the Goverment], and by the Interception of Communications Commissioner and the [[Intelligence Services Commissioner. Judicial oversight of the service's conduct is excerised by the Investigatory Powers Tribunal.

Operations of the service are required to be proportionate and compliant with British legislation including Regulation of Investigatory Powers Act 2000, Data Protection Act 1998 and various other items of legislation. Information held by the service is exempt from disclosure under section 23 of the Freedom of Information Act 2000.

The current Director General is Jonathan Evans, who succeeded Dame Eliza Manningham-Buller on 8 April 2007.

The service has marked its centenary in 2009 by publishing an official history, written by Professor Christopher Andrew, Professor of Modern and Contemporary History at Cambridge University, published in hardback in October 2009 by Allen Lane, an imprint of Penguin Books.

Early years
The Security Service is derived from the Secret Service Bureau, founded in 1909 and concentrating early activities on the activities of the Imperial German government as a joint initiative of the Admiralty and the War Office. The Bureau was split into naval and army sections which, over time, specialised in foreign target espionage and internal counter-espionage activities respectively. This specialisation was a result of the Admiralty intelligence requirements related to the maritime strength of the Imperial German Navy. This specialisation was formalised prior to 1914 and the beginning of World War I, with the two sections undergoing a number of administrative changes and the home section becoming Directorate of Military Intelligence Section 5 (MI5), the name by which it is known in popular culture to this very day.

The founding head of the Army section was Captain Vernon Kell of the South Staffordshire Regiment, who remained in that role until the early part of the Second World War. Its role was originally quite restricted; existing purely to ensure national security through counter-espionage. With a small staff and working in conjunction with the Special Branch of the Metropolitan Police, the service was responsible for overall direction and the identification of foreign agents, whilst Special Branch provided the manpower for the investigation of their affairs, arrest and interrogation.

On the day after the declaration of war, the Home Secretary Reginald McKenna announced that "within the last twenty-four hours no fewer than twenty-one spies, or suspected spies, have been arrested in various places all over the country, chiefly in important military or naval centres, some of them long known to the authorities to be spies", a reference to arrests directed by the service. These arrests have provoked recent historical controversy. According to the official history of MI5, the actual number of agents identified was 22 and Kell had started sending out letters to local police forces on 29 July giving them advance warning of arrests to be made as soon as war was declared. Portsmouth Constabulary jumped the gun and arrested one on 3 August, and not all of the 22 were in custody by the time that McKenna made his speech, but the official history regards the incident as a devastating blow to Imperial Germany which deprived them of their entire spy ring, and specifically upset the Kaiser.

This view has been challenged by Nicholas Hiley who has asserted that it is a complete fabrication. In 2006 his article "Entering the Lists" was published in the journal Intelligence and National Security outlining the products of his research into recently opened files. Hiley was sent an advance copy of the official history and objected to the retelling of the story. He later wrote another article, "Re-entering the Lists", which asserted that the list of those arrested published in the official history was concocted from later case histories.

Inter-war period
After this auspicious start, the history of MI5 becomes darker. It was consistently successful throughout the rest of the 1910s and the 1920s in its core counter-espionage role. Germany continued to attempt to infiltrate Britain throughout the war, but using a method that depended on strict control of entry and exit to the country and, crucially, large-scale inspection of mail, MI5 was able to identify most of, if not all of, the agents dispatched. In post-war years attention turned to attempts by the Soviet Union and the Comintern to surreptitiously support revolutionary activities within Britain, and MI5's expertise combined with the early incompetence of the Soviets meant the bureau was successful once more in correctly identifying and closely monitoring these activities.

However, in the meantime MI5's role had been substantially enlarged. Due to the spy hysteria, MI5 was formed with far more resources than it actually needed to track down German spies. As is common within governmental bureaucracies, this meant it expanded its role in order to use its spare resources. MI5 acquired many additional responsibilities during the war. Most significantly, its strict counter-espionage role was considerably blurred. It became a much more political role, involving the surveillance not merely of foreign agents but of pacifist and anti-conscription organisations, and organised labour. This was justified on the basis of the common (but mistaken) belief that foreign influence was at the root of these organisations. Thus by the end of the war, MI5 was a fully-fledged investigating force (although it never had the powers of arrest), in addition to being a counter-espionage agency. This expansion of its role continued after a brief post-war power struggle with the head of the Special Branch, Sir Basil Thomson.

MI5's operations during the Irish War of Independence were an unmitigated disaster. Due to MI5's penchant for sharing intelligence with the Dublin Metropolitan Police, its Irish operations were easily penetrated by the Irish Republican Army. Using D.M.P. Detectives Ned Broy and David Nelligan, Michael Collins was able to learn the names and lodgings of the MI5 agents of the Cairo Gang. On Bloody Sunday (1920), Collins ordered his private death squad to assassinate 14 MI5 agents at their lodgings throughout Dublin. That afternoon, a mixed force of the British Army the Royal Irish Constabulary, and the Black and Tans retaliated by shooting up a Gaelic Football match at Croke Park.

In the aftermath, MI5 ceased sharing intelligence with the Dublin Metropolitan Police. In response, Collins persuaded Detective Nelligan to let himself be recruited into MI5. Although MI5's agents were shocked that a Catholic Irishman desired to work for them, Nelligan was formally sworn into the British Secret Service. He then memorized the oaths, codes, and lodgings of his fellow agents and passed the information on to Collins. Nelligan further delivered falsified reports stating that the IRA was far more numerous and better supplied with guns and ammunition than was actually the case. Nelligan would later recall in his memoirs that Collins was planning another Bloody Sunday style purge at the time a ceasefire ended the War.

MI5 operated in Italy during inter-war period. MI5 helped Benito Mussolini get his start in politics with the £100 weekly wage.

MI5's decline in counter-espionage efficiency began in the 1930s. It was to some extent a victim of its own success; it was unable to break the ways of thinking it had evolved in the 1910s and 1920s, in particular, to adjust to the new methods of the Soviet intelligence services the NKVD and GRU. It continued to think in terms of agents who would attempt to gather information simply through observation or bribery, or to agitate within labour organisations or the armed services, while posing as ordinary citizens. The NKVD, however, had evolved more sophisticated methods; it began to recruit agents from within the British nobility, most notably from Cambridge University, who were seen as a long-term investment. They succeeded in gaining positions within the Government (and, in Kim Philby's case, within British intelligence itself), from where they were able to provide the NKVD with sensitive information. The most successful of these agents—Harold "Kim" Philby, Donald Maclean, Guy Burgess, Anthony Blunt and John Cairncross—went undetected until after the Second World War, and were known as the Cambridge Five.

Second World War
MI5 experienced further failure during the Second World War. It was chronically unprepared, both organisationally and in terms of resources, for the outbreak of war, and utterly unequal to the task which it was assigned—the large-scale internment of enemy aliens in an attempt to uncover enemy agents. The operation was poorly handled and contributed to the near-collapse of the agency by 1940. One of the earliest actions of Winston Churchill on coming to power in early 1940 was to sack the agency's long-term head, Vernon Kell. He was replaced initially by the ineffective Brigadier A.W.A. Harker, as Acting Director General. Harker in turn was quickly replaced by David Petrie, an SIS man, with Harker as his deputy. With the ending of the Battle of Britain and the abandonment of invasion plans (correctly reported by both SIS and the Bletchley Park Ultra project), the spy scare eased, and the internment policy was gradually reversed. This eased pressure on MI5, and allowed it to concentrate on its major wartime success, the so-called "double-cross" system.

This was a system based on an internal memo drafted by an MI5 officer in 1936, which criticised the long-standing policy of arresting and sending to trial all enemy agents discovered by MI5. Several had offered to defect to Britain when captured; before 1939, such requests were invariably turned down. The memo advocated attempting to "turn" captured agents wherever possible, and use them to mislead enemy intelligence agencies. This suggestion was turned into a massive and well-tuned system of deception during the Second World War.

Beginning with the capture of an agent named Owens, codenamed Snow, MI5 began to offer enemy agents the chance to avoid prosecution (and thus the possibility of the death penalty) if they would work as British double-agents. Agents who agreed to this were supervised by MI5 in transmitting bogus "intelligence" back to the German secret service, the Abwehr. This necessitated a large-scale organisational effort, since the information had to appear valuable but actually be misleading. A high-level committee, the Wireless Board, was formed to provide this information. The day-to-day operation was delegated to a subcommittee, the Twenty Committee (so called because the Roman numerals for twenty, XX, form a double cross).

The system was extraordinarily successful. A postwar analysis of German intelligence records found that of the 115 or so agents targeted against Britain during the war, all but one (who committed suicide) had been successfully identified and caught, with several "turned" to become double agents. The system played a major part in the massive campaign of deception which preceded the D-Day landings, designed to give the Germans a false impression of the location and timings of the landings (see Operation Fortitude).

All foreigners entering the country were processed at the London Reception Centre (LRC) at the Royal Patriotic School which was operated by MI5 subsection B1D, 30,000 were inspected at LRC. Captured enemy agents were taken to Camp 020, Latchmere House, for interrogation. This was commanded by Colonel Robin Stephens. There was a Reserve Camp, Camp 020R, at Huntercombe which was used mainly for long term detention of prisoners.

Post-war: The Troubles in Northern Ireland
The Prime Minister's personal responsibility for the Service was delegated to the Home Secretary Maxwell-Fyfe in 1952, with a directive issued by the Home Secretary setting out the role and objectives of the Director-General. The service was subsequently placed on a statutory basis in 1989 with the introduction of the Security Service Act. This was the first government acknowledgement of the existence of the service.

The post-war period was a difficult time for the Service with a significant change in the threat as the Cold War began, being challenged by an extremely active KGB and increasing incidence of the Northern Ireland conflict and international terrorism. Whilst little has yet been released regarding the successes of the service there have been a number of intelligence failures which have created embarrassment for both the service and the government. For instance in 1983 one of its officers, Michael Bettaney, was caught trying to sell information to the KGB. He was subsequently convicted of espionage.

Following the Michael Bettaney case, Sir Philip Woodfield was appointed as a staff counsellor for the security and intelligence services. His role was to be available to be consulted by any member or former member of the security and intelligence services who had "anxieties relating to the work of his or her service" that it had not been possible to allay through the ordinary processes of management-staff relations, including proposals for publications.

The Service was instrumental in breaking up a large Soviet spy ring at the start of the 1970s, with 105 Soviet embassy staff known or suspected to be involved in intelligence activities being expelled from the country in 1971.

One episode involving MI5 and the BBC came to light in the mid-1980s. MI5 officer, Brigadier Ronnie Stonham, had an office in the BBC and took part in vetting procedures.

Controversy arose when it was alleged that the service was monitoring trade unions and left-wing politicians. A file was kept on Labour Prime Minister Harold Wilson from 1945, when he became an MP, although the agency's official historian, Christopher Andrew maintains that his fears of MI5 conspiracies and bugging were unfounded. As Home Secretary the Labour MP Jack Straw discovered the existence of his own file dating from his days as a student radical.

One of the most significant and far reaching failures was an inability to conclusively detect and apprehend the "Cambridge Five" spy ring which had formed in the inter-war years and achieved great success in penetrating the government, and the intelligence agencies themselves. Related to this failure were suggestions of a high-level penetration within the service, Peter Wright (especially in his controversial book Spycatcher) and others believing that evidence implicated the former Director-General himself, Roger Hollis. The Trend inquiry of 1974 cleared Hollis of that accusation, but it was later corroborated by the former KGB officer Oleg Gordievsky. Another spy ring, the Portland Spy Ring, exposed after a tip-off by Soviet defector Michael Goleniewski, led to an extensive MI5 surveillance operation.

The Security Service's role in counter-terrorism
The end of the Cold War resulted in a change in emphasis for the operations of the service, assuming responsibility for the investigation of all Irish republican activity within Britain and increasing the effort countering other forms of terrorism, particularly in more recent years the more widespread threat of Islamic extremism.

Whilst the British security forces in Northern Ireland have provided support in the countering of both republican and loyalist paramilitary groups since the early 1970s, republican sources have often accused these forces of collusion with loyalists. In 2006, an Irish government committee inquiry found that there was widespread collusion between British security forces and loyalist terrorists in the 1970s, which resulted in eighteen deaths.

The Security Service took responsibility for all security intelligence work in Northern Ireland from 2007 from the Police Service of Northern Ireland. Both Nuala O'Loan, the Police Ombudsman for Northern Ireland, and Al Hutchinson, the Oversight Commissioner of the Police Service of Northern Ireland, expressed reservations. During April 2010 the Real IRA detonated a 120 lb. car bomb outside Palace Barracks in County Down which is the headquarters of MI5 in Northern Ireland and also home to the 2nd Battalion The Mercian Regiment.

Executive Liaison Groups enable MI5 to safely share secret, sensitive, and often raw intelligence with the police, on which decisions can be made about how best to gather evidence and prosecute suspects in the courts. Each organization works in partnership throughout the investigation, but MI5 retain the lead for collecting, assessing and exploiting intelligence. The police take lead responsibility for gathering evidence, obtaining arrests and preventing risks to the public.

Serious crime
In 1996, legislation formalised the extension of the Security Service's statutory remit to include supporting the law enforcement agencies in their work against serious crime. Tasking was reactive, acting at the request of law enforcement bodies such as the National Criminal Intelligence Service (NCIS), for whom MI5 agents performed electronic surveillance and eavesdropping duties during Operation Trinity. This role has subsequently been passed to the Serious Organised Crime Agency (SOCA).

Surveillance
In July 2006, Norman Baker MP accused the British Government of "hoarding information about people who pose no danger to this country", after it emerged that MI5 holds secret files on 272,000 individuals—equivalent to one in 160 adults. It was later revealed that a "traffic light" system operates:
 * Green: active—about 10% of files
 * Amber: enquiries prohibited, further information may be added—about 46% of files.
 * Red: enquiries prohibited, substantial information may not be added—about 44% of files

Directors-General of the Security Service

 * 1909–1940: Sir Vernon Kell (from 1919, Sir Vernon Kell) (b. 1873–d. 1942)
 * 1940–1941: Brigadier Oswald Allen Harker (b. 1886–d. 1968)
 * 1941–1946: Sir David Petrie (b. 1879–d. 1961)
 * 1946–1953: Sir Percy Sillitoe (b. 1888–d. 1962)
 * 1953–1956: Sir Dick White (from 1955, Sir Dick White) (b. 1906–d. 1993)
 * 1956–1965: Sir Roger Hollis (from 1960, Sir Roger Hollis) (b. 1905–d. 1973)
 * 1965–1972: Sir Martin Furnival Jones (from 1967, Sir Martin Furnival Jones) (b. 1912–d. 1997)
 * 1972–1979: Sir Michael Hanley (from 1974, Sir Michael Hanley) (b. 1918–d. 2001)
 * 1979–1981: Sir Howard Smith (b. 1919–d. 1996)
 * 1981–1985: Sir John Jones (b. 1923–d. 1998)
 * 1985–1988: Sir Antony Duff (b. 1920–d. 2000)
 * 1988–1992: Sir Patrick Walker (from 1990, Sir Patrick Walker) (b. 1932)
 * 1992–1996: Dame Stella Rimington (from 1996, Dame Stella Rimington) (b. 1935)
 * 1996–2002: Sir Stephen Lander (from 2000, Sir Stephen Lander) (b. 1947)
 * 2002–2007: Dame Eliza Manningham-Buller (now Baroness Manningham-Buller; b. 1948)
 * 2007–present: Jonathan Evans

Past names of the Security Service
Although commonly referred to as "MI5", this was the Service's official name for only thirteen years (1916–29). However, as an acknowledgment of popular thought, "MI5" is used as a sub-title on the various pages of the official Security Service website (see links, below).
 * October 1909: Founded as the Home Section of the Secret Service Bureau.
 * April 1914: Became a subsection of the War Office Directorate of Military Operations, section 5 (MO5)—MO5(g).
 * September 1916: Became Military Intelligence section 5—MI5.
 * 1929: Renamed the Defence Security Service.
 * 1931: Renamed the Security Service.