Afghanistan: The Enduring Stain on the British State

The fourth Anglo-Afghan conflict (2001-21) is a dark period in British military history which is getting bleaker. The continuing impact of the conflict on UK national security stems from a refusal to confront and learn from the past. The 2025 Strategic Defence Review (SDR) focus was to reconstitute UK warfighting capability to deter and defeat Russia. However, the legacy of Afghanistan will continue to jeopardise this vision unless the British State owns – and learns from – its mistakes.

Compounding Failures

The UK spent an estimated £22.9 billion (£32.8 billion when adjusted for inflation) on Afghanistan between 2001 and 2021, with the latest data leak reportedly costing an additional £850 million. For this reason alone, the British public deserve accountability, but there are multiple reasons why the UK must be held to account for its actions. Added up, they amount to a comprehensive British whole-of-system failure.

First, the 2001-14 International Security Assistance Force (ISAF) failed to secure the country for the new Afghan government to govern. The UK contingent – Operation Herrick – was a war of choice which lacked a single campaign strategy and ignored the master principle of war – the selection and maintenance of the aim. As such, mission creep expanded the operation which, at times, included counter insurgency, counter terrorism, stabilisation, humanitarian aid and counter narcotics. As an example, since the Taliban regained control of the country, between 2022 and 2023, poppy cultivation under the Taliban reduced by more than 99%. The UK talked of counter insurgency but never got anywhere near the development and reconstruction resources required, mainly because the security operation was consistently underpowered.

Concepts of operations were changed every six months as new Brigades rotated through and new Commanders wanted to make their mark. Most operations were ground holding, but Helmand was never vital ground or key terrain – either for ISAF or the Taliban. The 2006 decision to widely expand ISAF across the country was led by the UK, alongside Canada and the Netherlands as the US was distracted in Iraq. In a uniquely British fashion, insufficient resources were allocated. The original combat estimate for the size of force needed for Helmand in 2006 was a brigade, but Permanent Joint Headquarters asked the planners to revise down to a battle group. The MoD then made a hollow virtue of getting on with the tools it had and became isolated in checkpoints of peripheral value across the green zone. British operations between 2007 and 2014 were in effect one very long withdrawal operation. Like in Iraq, UK forces in the south were ultimately bailed out by US reinforcements.

Second, the 2015-21 NATO Resolute Support Mission (RSM) failed to build a resilient state or an Afghan National Army that could underpin it. The UK’s 'Sandhurst in the Sand' officer training facility in Kabul was lauded for exporting British leadership standards and professionalism, training over 3,000 officers between 2013 and 2018. However, these admittedly well-trained officers completely vanished in the onslaught of Taliban offensives over the summer of 2021 as they were ill-equipped to deal with the most likely scenario when coalition forces withdrew.

Third, Operation Pitting – the August 2021 evacuation from Kabul – was a whole-of-government failure. The brave men and women of 16 Air Assault Brigade did their jobs in an exemplary fashion in very challenging circumstances. However, poor preparation and coordination between the MoD, FCDO, and Home Office failed to establish a functioning scheme to evacuate Afghans that were at severe risk of Taliban reprisals.

A spokesperson stated that ‘UK government staff worked tirelessly to evacuate more than 15,000 people from Afghanistan within a fortnight. This was the biggest mission of its kind in generations’. However, multiple whistleblower testimonies, including one from a Civil Servant who subsequently won an unlawful dismissal case against the UK government after speaking to the BBC about failures, described internal chaos within the FCDO exemplified by the prioritisation of the evacuation of stray dogs from the Nowzad animal shelter. Decision making was compromised due to multiple seniors being on holiday including: The Foreign Secretary, the Permanent Secretaries of the FCDO and the MoD, and the Minister for Afghanistan.

The lack of preparation was a failure of politicians to interpret the available intelligence. The withdrawal of US forces was long telegraphed by successive administrations and President Biden advocated for it while Vice President in 2009. Unlike the US and UK, France interpreted the intelligence dispassionately and started the process of repatriation early summer, which spared them the chaos and indignity of the Kabul airlift.

Fourth, the Afghan Relocation Assistance Policy (ARAP) and other resettlement schemes are fundamentally flawed, despite an estimated lifetime cost of £6bn and likely higher. Unable to cope with demand and slow at corroborating claimants’ family details, veterans have stepped in to help their former partners. Your authors’ interpreter and his family are still in hiding in Afghanistan today, with little hope of repatriation, over four years on from his original application.

The failure to prioritise the ‘Triples’ – Afghan Task Force 444 and Coalition Force 333 who did the heaviest fighting and more at risk of Taliban reprisals – which were raised, trained by and operated alongside UK Special Forces (UKSF) is shameful. Worse is the accusation that UKSF have deliberately blocked these relocation claims to prevent them being compelled to testify against UK soldiers accused of war crimes within Afghanistan. A single UKSF officer is said to have personally blocked 1,585 applications – each and every one assigned to him in the summer of 2023.

Fifth, actual war crimes and accusations of further incidents perpetrated by British forces. In 2014, Sergent Alexander Blackman – referred to as ‘Marine A’ in court proceedings – became the first UK soldier convicted of murder since the Second World War for killing an injured Taliban insurgent. The MoD were keen to paint this as an isolated incident. However, there have been widespread accusations of extrajudicial killings by UKSF in Afghanistan. An independent statutory inquiry, established in 2022 and led by Lord Justice Haddon-Cave, is investigating UKSF operations between mid-2010 and mid-2013. If Lord Haddon-Cave finds evidence of extrajudicial killings it would have severe implications for the British state. The Prime Minister would have to stand in the House and confirm to the world that British forces had committed war crimes. Worse still, he might also have to confirm attempts of a cover up.

Sixth, out of scope of Haddon-Cave – but equally damaging – is the accusations of a cover up of potential war crimes. The internal Royal Military Police investigation ‘Operation Northmore’ – which has cost £10 million – was told to ‘take no action’ over the deletion of data regarding the alleged unlawful killings. The accusation is that senior military officers were aware of the accusations and did not do enough to investigate.

Seventh, the July 2025 uncovering of the data breach - described as the most expensive email in history - was just one data breach of 49 in the past four years. Over 200 Afghans have been reported to have been killed since the breach and Iran has been accused of using the leaked list to hunt British spies. The super injunction that was used to silence the media and avoid accountability lasted three successive defence secretaries. The latest refused to rule out using the mechanism again.

Finally, a failure to care for veterans. 150,610 military personnel served in Afghanistan over 20 years from all three services. However, the MoD did not even record veteran suicides until 2021, despite data going back to the Falklands War highlighting it as a serious issue. Overall, there is no identifiable difference in the rate of suicide between male UK armed forces veterans and the male general population. However, male veterans aged 25-44 years had a higher rate of suicide compared to the same group in the general population. This is a critical group and likely to get worse without better care for veterans.

Avoiding Accountability and Failing to Learn Lessons

The UK has compounded these mistakes by being selective and institutionally protective in the lessons Britain should draw from the Afghanistan campaign and unwilling to ask tough questions and hold people to account. This is in direct contrast to the US approach after the Vietnam war. The US confronted directly the causes and the scale of the failure they had just lived through, and they made structural, doctrinal, societal and long-term changes to how their army functions. In the UK, there has been no legitimate lessons learned process and no public inquiry (with the exception of Haddon-Cave), with only a handful of reactive Parliamentary committees to shine some light on it. This refusal to learn will create future challenges for the UK military’s moral component and its ability to fight.

First, enthusiastically fighting a conflict that was peripheral to UK security and interests has hollowed out the UK’s ability to fight a major industrial war. Despite identifying in 2015 that Afghanistan had ‘bent the army out of shape’, reconstituting British warfighting power has been incredibly slow. Moreover, many veterans of the conflict have now left service, leaving the army ‘greener’ than it has ever been since the end of the Cold War. In short, fighting in Afghanistan made the UK much less prepared for fighting Russia. Second, it will be challenging for the UK to build up a Strategic Reserve as society is less willing to fight. The SDR called for a ‘whole of society approach’ to defence, but younger generations now associate the military and NATO with failure in Afghanistan, rather than prevailing over the Soviet Union. Third, if UKSF are found guilty of extra judicial killings then it will seriously harm their ability to operate and recruit. It will seriously compromise the whole of the UK military and its moral component of fighting power. Moreover, the latest data breaches contained UK Intelligence Community data, likely creating distrust in the future of the relationship between the two. Fourth, the UK made promises to allies and partners that it did not keep. Therefore, why would any partner force trust the UK again? In this context, the current government mantra to support Ukraine for 'as long as it takes' rings hollow.

A Grim Legacy

In the 2010 annual RUSI Chief of Defence Staff lecture, now Field Marshall Baron Richards of Herstmonceux stated:

‘I agree wholeheartedly with the Secretary of State that failing to win the war we currently fight would be a betrayal of the armed forces, the British people and our national security.’

The armed forces – especially veterans – and the British people should rightly feel betrayed. This failure has damaged the prospect of public trust, understanding and fortitude when the British States asks people to endure the next war and the UK’s reputation as a fighting force. The centrality to UK defence of ISAF led it to become its ‘Main Effort’ under ‘Operation Entirety’. To put the failure in an avowedly military context, it was not just mission failure, it was a whole system failure. Failing in your Main Effort is terminal for a Commander. It is also symptomatic of a British system which actively avoids scrutiny and accountability.

RUSI has already produced a study on retaining the hard-won lessons of Afghanistan, yet the MoD has consistently avoided such analysis. However, for the MoD and UK government, such an undertaking would be less about the product than the process, and helping to develop a culture of challenge, introspection and honesty to improve decision-making.

Finally, the central SDR outcome was the UK adopting a ‘NATO First’ strategy and Afghanistan was NATO’s largest and most ambitious operation ever. Other allies have sought to learn as much as possible from their involvement to improve their approaches, not just to military operations, but political decision-making, fighting as an alliance, and maintaining unity – all very prescient to the challenges facing Europe today. Moreover, this process would hopefully remind politicians and generals of the limits of military power - just as planning for a Reassurance Force to deploy to Ukraine takes place – to ensure that the potential Coalition of the Willing does not make the same mistakes.

© RUSI, 2025.

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