MI5


The Security Service, commonly known as MI5, is the United Kingdom's domestic counter-intelligence and security agency and is part of its intelligence machinery alongside the Secret Intelligence Service, Government Communications Headquarters, and Defence Intelligence. MI5 is directed by the Joint Intelligence Committee, and the service is bound by the Security Service Act 1989. The service is directed to protect British parliamentary democracy and economic interests and to counter terrorism and espionage within the United Kingdom. Within the civil service community, the service is colloquially known as Box, or Box 500, after its official wartime address of PO Box 500; its current address is PO Box 3255, London SW1P 1AE.
The Security Service began as the Home Section of the Secret Service Bureau, founded in 1909. At the start of the First World War, it was responsible for the arrest of enemy spies, or suspected enemy spies. Throughout the First World War, Germany continually attempted to infiltrate Britain, but MI5 was able to identify most, if not all, of the agents dispatched. During the Second World War, it developed the Double-Cross System. This involved attempting to "turn" captured agents wherever possible, and use them to mislead enemy intelligence agencies.
After the war, the service was instrumental in breaking up a large Soviet spy ring at the start of the 1970s. It then allegedly became involved in monitoring trade unions and left-wing politicians. It also assumed responsibility for the investigation of all Irish republican activity within Britain during The Troubles. Its role was then expanded to countering other forms of terrorism, particularly in more recent years the more widespread threat of Islamic extremism. 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.

Organisation

Structure

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 Civil Service, who is directly supported by an internal security organisation, secretariat, legal advisory branch, and information services branch. The Deputy Director General is responsible for the operational activity of the service, being responsible for four branches; international counter-terrorism, National Security Advice Centre, Irish and domestic counter-terrorism, and technical and surveillance operations.
The current Director General is Ken McCallum, who succeeded Andrew Parker in April 2020.
The service is directed for intelligence operational priorities by the Joint Intelligence Committee.

Legislation

Operations of the service are required to be proportionate, and compliant with British legislation, including the Regulation of Investigatory Powers Act 2000, the Investigatory Powers Act 2016, the Data Protection Act 2018, 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 Security Service Act of 1989 establishes several legal key mechanisms aimed at ensuring the accountability and control of the Service. Certain provisions from this act were later integrated into the Intelligence Services Act of 1994 with European Commission on Human Rights later having endorsed these mechanisms in multiple applications under the European Convention on Human Rights. Additionally, all employees of the service are bound by the Official Secrets Act.
The Security Service "is authorised to investigate any person or movement that might threaten the... security" of the United Kingdom.

Oversight

The Service is subject to oversight and accountability through various means. These oversight mechanisms have evolved over time to meet changing governmental requirements, with the Service now being held accountable through a variety of oversight arrangements.
It is directly answerable to the Home Secretary, and is also overseen by:
The service marked its centenary in 2009 by publishing an official history titled The Defence of the Realm: The Authorized History of MI5, written by Christopher Andrew, Professor of Modern and Contemporary History at Cambridge University. Members of the Security Service are recognised annually by King Charles III at the Prince of Wales's Intelligence Community Awards at St James's Palace or Clarence House alongside members of the Secret Intelligence Service, and GCHQ. Awards and citations are given to teams within the agencies as well as individuals.

History

Early years

The Security Service is derived from the Secret Service Bureau, founded in 1909, and concentrating originally on the activities of the Imperial German government, as a joint initiative of the Admiralty and the War Office. The Bureau was initially split into naval and army sections which, over time, specialised respectively in foreign target espionage and internal counter-espionage activities. The former specialisation was a result of a growing interest at the Admiralty, at the time, in intelligence regarding the fleet of the Imperial German Navy. This division was formalised, as separate home and foreign sections, prior to the beginning of the First World War. Following a number of administrative changes, the home section became known as Directorate of Military Intelligence, Section 5 and the abbreviation MI5, the name by which it is still known in popular culture..
The founding head of the Army section was 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, as the section existed solely 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, while Special Branch provided the manpower for the investigation of their affairs, arrest and interrogation.

First World War

On the day after the declaration of the First World 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". 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.
However, in 2006, historian Nicholas Hiley published an article entitled "Entering the Lists" in the journal Intelligence and National Security, outlining the products of his research into recently opened files on spies arrested at the start of the First World War. 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.
In the meantime, MI5's role had grown substantially. Due to the spy hysteria, MI5 had formed with far more resources than it actually needed to track down German spies. As is common within governmental bureaucracies, this caused the service to expand its role to use its spare resources. MI5 acquired many additional responsibilities during the war. Most significantly, its strict counter-espionage role blurred considerably. It acquired a much more political role, involving the surveillance not merely of foreign agents, but also of pacifist and anti-conscription organisations, and of organised labour. This was justified by citing the common belief that foreign influence was at the root of these organisations. Thus, by the end of the First World War, MI5 was a fully-fledged investigating force, in addition to being a counter-espionage agency. The expansion of this role continued after a brief post-war power struggle with the head of the Special Branch, Sir Basil Thomson.

Inter-war period

MI5 proved consistently successful throughout the rest of the 1910s and 1920s in its core counter-espionage role. In post-war years, attention turned to attempts by the Soviet Union and the Comintern to surreptitiously support revolutionary activities within Britain. MI5's expertise, combined with the early incompetence of the Soviets, meant the bureau was successful in correctly identifying and closely monitoring these activities.
After the First World War, budget-conscious politicians regarded Kell's department as unnecessary. In 1919, MI5's budget was slashed from £100,000 to just £35,000, and its establishment from over 800 officers to a mere 12. At the same time, Sir Basil Thomson of Special Branch was appointed Director of Home Intelligence, in supreme command of all domestic counter-insurgency and counter-intelligence investigations. Consequently, as official MI5 historian Christopher Andrew has noted in his official history Defence of the Realm, MI5 had no clearly defined role in the Irish War of Independence of 1919–1921. To further worsen the situation, several of Kell's officers defected to Thomson's new agency, the Home Intelligence Directorate. MI5 therefore undertook no tangible intelligence operations of consequence during the conflict. MI5 did undertake the training of British Army case-officers from the Department of Military Intelligence, for the Army's so-called "Silent Section", otherwise known as M04.
In 1921, Sir Warren Fisher, the government inspector-general for civil-service affairs, conducted a thorough review of the operations and expenditures of Basil Thomson's Home Intelligence Directorate. He issued a scathing report, accusing Thomson of wasting both money and resources, and conducting redundant as well as ineffectual operations. Shortly thereafter, in a private meeting with Prime Minister David Lloyd George, Sir Basil Thomson was sacked, and the Home Intelligence Directorate was formally abolished. With Thomson out of the way, Special Branch was returned to the command of the Commissioner of The Criminal Investigation Division at Scotland Yard. Only then was Vernon Kell able once again to rebuild MI5 and restore it to its former place as Britain's chief domestic intelligence agency.
MI5 operated in Italy during the inter-war period, and helped Benito Mussolini get his start in politics with a £100 weekly wage. MI5's efficiency in counter-espionage declined in the 1930s. It was to some extent a victim of its own success, as it was unable to break the ways of thinking it had evolved in the 1910s and 1920s. In particular, it was unable to adjust to the new methods of the Soviet intelligence services, the People's Commissariat for Internal Affairs and Main Intelligence Directorate. 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 and the armed services, while posing as ordinary citizens. The NKVD, meanwhile, had evolved more sophisticated methods; it began to recruit agents from within the upper classes, whom it regarded as a long-term investment. Such NKVD agents 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; Philby, Donald Maclean, Guy Burgess, Anthony Blunt, and John Cairncross; went undetected until after the Second World War, and became known as the Cambridge Five.