Megan Karlshøj-Pedersen

11 May 2020

Authors' note: Thanks to Jamie Gaskarth, Paul Rogers, and Emily Knowles for their help with this Explainer (all mistakes are the author’s own).

Special forces (SF) are elite soldiers found in militaries across the world. These troops are “highly trained and specially equipped” with “the ability to infiltrate into hostile territory through land, sea, or air to conduct a variety of operations, many of them classified.” They often undertake such tasks in support of conventional troops, but also at times act as the sole deployment in high-value areas where the UK is not at war, but still wishes to address instability to further its foreign policy interests.

As a result of the type of tasks that special forces undertake, they often operate with some degree of secrecy. As a result, while Hollywood has provided much food for the imagination, it is often difficult to understand what these forces actually do, where in the world they are operating, and how their actions fit into wider strategies. This is especially true in the UK, where the government and Ministry of Defence refuse to comment on its special forces.

This explainer will focus specifically on the UK’s special forces (UKSF), examining what we do know about them, what they do, their history, what they cost, and the UK’s policies towards them. To set this information in context, examples from the special forces of the United States will be used throughout the explainer; while these two forces differ significantly in many ways, as will be explored further below, they are historically interlinked and continue to operate in similar theatres.


UKSF are formed of three dedicated SF units: the Special Air Service (SAS), the Special Reconnaissance Regiment (SRR), and the Special Boat Service (SBS).  The Special Forces Support Group (SFSG) was set up in 2006 to assist the three SF units above, yet it is not made up of SF operatives. Instead it consists of elite forces from units such as the Parachute Regiment and the Royal Marines who operate closely alongside SF operatives; for instance, they have been reported as working on the ground alongside the SBS in places like Sirte, Libya in 2016, in connection with strikes against ISIS.

To become a member of UKSF, candidates must go through a notoriously challenging selection process. This twice-yearly process extends over five months, and includes a month spent in jungle environments as well as intense interrogation training; this is meant to test both physical and mental endurance. The vast majority of candidates do not pass these tests, often due to stress or injuries. The candidates who do make it through selection – reported to be less than 10% - are passed on to operational squadrons for further training before being deployed.

Very little information is released by the British Government on UKSF, yet various leaks and reports by mainstream media do provide some sense of the size of the forces (thought to be between 2000 – 3000) as well as the kind of tasks these specialist troops tend to undertake. While there is no contemporary official document outlining the kind of tasks that UKSF undertake, a leaked Ministry of Defence (MoD) memo from 1969 sets out the SAS’ likely tasks as follows:

  1. The collection of information on the location and movement of insurgent forces;
  2. The ambush and harassment of insurgents;
  3. Infiltration of sabotage, assassination and demolition parties into insurgent-held areas;
  4. Border surveillance;
  5. Limited community relations;
  6. Liaison with, and organisation, training and control of, friendly guerrilla forces operating against the common enemy.

To some degree, many of these are still among the tasks that UKSF undertake. Yet there are also significant differences; for example, several stories have been leaked in recent years which show that building the capacity of local and regional security partners has become a significant focus of UKSF – as well as of the rest of British defence. In 2019 alone, it has been reported that UKSF are training – and at times, working alongside - local forces in Yemen, Syria, and Kenya. As UKSF become increasingly relied upon, it is important to understand their history and how they have become the force they are today.  

Scroll over map and go to bottom right corner to enlarge


UKSF were first established during World War II, where they were perceived to be useful in operations in peripheral theatres, for ‘ad hoc’ use behind enemy lines, and in advance of conventional troops in mainland Europe and beyond. Arguably, the most famous UKSF unit was – and remains - the Special Air Service (SAS), which was formed to help the British Army in its fight against the Axis forces fighting in North Africa. In the aftermath of WWII, the SAS was disbanded on the assumption that such forces would no longer be required. Yet just a few years later, they were reformed during the Malayan Emergency (1948-1960). In this war, their ability to engage in “deep penetration missions in a jungle” environment was thought more effective than conventional forces.

In parallel to the Malayan Emergency, political instability elsewhere in the British Empire during the 1940s also contributed to calls for an unconventional military force to be permanently established. Spiralling violence in Palestine during 1947, for example, led to calls that “some type of special force was necessary, but to be useful, it had also to be ‘expendable’”. That same year, a reserve SAS unit (the 21st) was created.

These calls only increased after the 1940s, and by 1959 the SAS had added a permanent unit (the 22nd) and another reserve unit (the 23rd) to its ranks. These forces went on to play an important and  controversial role during the Troubles in Northern Ireland throughout the conflict. The British public’s fascination with UKSF was cemented in 1980 when these forces freed the majority of hostages taken by six gunmen at the Iranian embassy in London. In 2000, when British soldiers and their Sierra Leone Army Liaison Officer were captured by a rebel group, the UKSF operation which rescued the soldiers was seen as further evidence of the effectiveness of the SF approach. During the following decade, the UKSF became a permanent ‘mini fourth branch of the [British] Armed Forces’.

The last two decades have truly become “the golden age of special operations.” This development started after the 9/11 terrorist attacks, when the US-led coalition intervened in Iraq and Afghanistan and special forces from multiple countries played a prominent role. While it was conventional forces which led on these conflicts, SF acted as a potent support force. Then, as political support for these wars dwindled, and the 2008 financial crisis led to national military budgets being de-prioritised, the utility of SF increased again as Western governments looked for alternatives to meet perceived national security challenges without a negative political backlash. Seen by many to be low-cost and low-risk, these forces were the apparently perfect solution.

Today, SF no longer focus on the very short-term, specialised tasks that defined their activities in earlier campaigns. Instead, they have - at times - come to represent the main component of some nations’ responses to crises and instability abroad, often staying persistently engaged for long stretches of time. For instance, in May 2016 the UK Secretary of State for Defence told the UK House of Commons “we do not intend to deploy ground forces in any combat role” in Libya, however media reports indicated that UKSF had been spearheading a “secret war” against IS in the country for at least the last three months.

The role of UK special forces may once again be undergoing significant changes. During the summer of 2019, an increasing number of media outlets reported that UKSF’s role was being revised by the Director of Special Forces in his ‘Special Operations Concept’. It was reported that this Concept would look at how UKSF could address threats from states such as Russia and Iran. According to the Concept, “an operation might be mounted in a Baltic republic or African country [by UK special forces] in order to uncover and pinpoint Russian covert activities.” Similarly, at the inaugural conference of the cross-service strategic command, Minister for Armed Forces, James Heappey, outlined that UKSF would move away from “crawling through the ditch with their dagger in their teeth ready to plunge it into the heart of the enemy commander” and instead “plant malware in the heart of enemy servers”. He also emphasised that these forces would take on an even greater share of the British defence effort in the future.  

UK policy surrounding special forces

Despite the burgeoning role played by UKSF in contemporary conflicts, and in contrast to its allies, there is no public or parliamentary oversight over the deployments of UKSF, their effectiveness, their actual costs, accountability mechanisms, or how their deployments fit into a wider strategy. While the Intelligence and Security Committee (ISC) offers some oversight over the secretive intelligence agencies of the UK, its remit does not cover UKSF; nor does the remit of the Defence Committee, or any other parliamentary committee. In general terms, of course, the Ministry of Defence and all parts of the armed forces are accountable to Parliament through government ministers and may be asked to give statements to the House of Commons. However, in practice, any direct scrutiny over their activities are strictly limited by the UK Government’s long-held policy to not comment on SF or their operations.

This lack of transparency is exacerbated by UKSF’s exemption from the Freedom of Information Act, and the fact that anyone who leaks information on UKSF to the media is open to prosecution under the Official Secrets Acts. This is not to say that stories are not leaked; stories of UKSF operations regularly appears in the British media, including stories of UKSF successes apparently leaked by UKSF operatives themselves. Yet the usual mechanisms for eliciting comment and scrutinising government activity do not apply when it comes to these forces. This constitutes a severe limitation on the public debate on UKSF; it is also a significant hindrance to MPs who wish to debate the issue but are simply met with a “no comment” approach.

This also means that UKSF are rarely discussed in the House of Commons. A notable exception to this rule was a recent debate on UKSF in light of allegations by the BBC’s Panorama programme and the Sunday Times that UKSF had carried out severe human rights abuses in Iraq and Afghanistan. Yet even in this debate, the Minister for Defence People and Veterans, Johnny Mercer, emphasised that as a result of the MOD’s ‘no comment’ policy, “I am … unable to speak in any detail about the vital role that our special forces played in Iraq and Afghanistan.”

ORG has argued elsewhere that there are dangers to such secrecy in the UK, for understanding the strategy they support and mitigating potential dangers of their overuse

How much?

There is no public information on how much UKSF cost, how this compares to other forces, and whether UKSF are cost-effective. In the US, where statistics on special forces are more widely available than they are in the UK, the data clearly shows the increased reliance on SF; from 2001 to 2011, funding for US SF more than doubled, and the number of US SF (70,000) in January 2017 represented a 50% increase in manpower since 2001. During the Trump Administration, this trend has continued; in 2020, the US Special Operation Forces military budget increased by 11%, bringing the budget for Fiscal Year 2020 up to $13.7 billion. For Fiscal Year 2021, these forces have requested $16.6 billion as they shift their attention to “find the right balance between continuing to challenge terrorist organizations while simultaneously addressing growing irregular warfare threats posed by nation-states.” Such budgetary bids are not comparable to British military budgets in terms of sheer numbers, but clearly illustrate the increased reliance on SF that has also been seen in the UK.

While such data is not available in the UK, a Ministry of Defence Study leaked in 2013 made clear that there was significant pressure to increasingly rely on UKSF. To get around challenges posed by a “risk averse public”, the study emphasised that “investing in greater numbers of SF” would be a step in the right direction. This advice appears to have been followed.

The 2015 National Security Strategy and Strategic Defence and Security Review (SDSR) contained a pledge to double investment in UKSF equipment, which amounted to £2 billion in new funding. In 2017, PM Theresa May pledged an additional £300m to bring SF up to full strength. These investments came in the context of media reports that UKSF had been understaffed and underfunded for several years. Without a baseline budget and follow-up reports, however, it is difficult to put these investments into context and understand what impact they may have had.

Funding of SF has not been clarified by the Chancellor’s 2019 Spending Round. While it pledged another £2.2bn to UK defence, the declassified report on the Modernising Defence Programme did not refer to UKSF budgets.


While much UKSF activity is secret, it is clear that they have taken on a significant part of the UK’s military response to instability abroad, being perceived by policymakers as low-cost and low-risk. In fact, their significance has been such that the post-9/11 era has been dubbed the “Golden Age of Special Forces.” It is also clear that this is not a temporary development; there is ample evidence that their responsibilities are likely to expand as UK national security priorities shift. Understanding who they are and what they do is therefore more important than ever. However, this continues to be difficult in the face of the limited information available on UKSF in the public sphere.

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Image credit: U.S. Army photo by Master Sgt. Michel Sauret. 

About the author

Megan Karlshoej-Pedersen is the Research and Policy Officer at ORG's Remote Warfare Programme.