Without long-term funding, institutional reform and strengthened oversight, Britain risks drifting from what the Intelligence and Security Committee describes as a state of “managed vulnerability” toward long-term decline.
Britain’s intelligence and national security apparatus is operating at the edge of its structural capacity just as geopolitical threats multiply, according to the Intelligence and Security Committee’s (ISC) Annual Report for 2023–2025. While the UK continues to achieve tactical successes and has updated elements of its legislative framework, the report paints a sobering picture of a system increasingly reliant on short-term fixes, crisis redeployments and implicit risk acceptance rather than sustained investment and reform.
At the heart of the ISC’s findings is a stark conclusion: the UK can no longer meet all its national security demands simultaneously. Chronic recruitment shortfalls across intelligence agencies, under-resourced oversight mechanisms and political reluctance to confront difficult trade-offs have left the system overstretched.
A security system at its limits
Adam Irwin, Managing Partner of Strategic Insight at Heligan Group said: “Recruitment failures are no longer framed as temporary, but systemic. During the reporting period, the Joint Intelligence Organisation filled only 13 of 61 planned posts. GCHQ recruited 774 staff against a target of 1,131; MI5 726 against 797; and the National Security Secretariat reached just 64 of 112 roles. These gaps have forced permanent triage, prioritising immediate crises over long-term capacity building.
“The war in Ukraine illustrates the consequences. Following Russia’s invasion in 2022, GCHQ and Defence Intelligence surged significant resources toward Ukraine-related tasks. Those redeployments were never reversed, and recruitment pipelines failed to compensate. As a result, coverage in other regions declined and major projects, including Defence Intelligence estate consolidation and the modernisation of RAF Digby, were delayed. The ISC concludes these slippages reflect the system’s true constrained capacity, not temporary crisis management.”
China: security diluted by economic caution
Irwin continued: “The UK’s response to China exposes political hesitation. The ISC’s long-delayed China Report in 2023 concluded that Beijing operates the world’s largest intelligence apparatus under a “whole-of-state” model, penetrating “every sector of the UK economy” through investment, supply chains and covert activity.
“Despite this, the Government has responded slowly and unevenly. Responsibility for overt economic influence has remained fragmented across under-resourced departments, and China has not been placed in the Enhanced Tier of the Foreign Influence Registration Scheme (FIRS), unlike Iran and Russia. The Committee suggests this reflects a deliberate choice to prioritise economic stability and diplomatic flexibility over closing a recognised security vulnerability.”
Iran and Russia: intensity versus capacity
“Iran presents a more direct threat,” says Irwin. “MI5 has identified at least 15 credible kidnap or assassination plots linked to Iran since 2022, alongside Iranian-linked attacks on Jewish and Israeli targets in Europe. While the UK has responded with sanctions, expulsions and an Enhanced Tier FIRS designation, the ISC highlights major legal gaps. In particular, the Government’s retreat from reforming the Official Secrets Act 1989 is described as deeply concerning, given its limitations in prosecuting espionage.
“Russia underscores the cost of operating within capped resources. Intelligence focus on Ukraine has inevitably reduced attention elsewhere, with recruitment shortfalls preventing effective backfilling. While agencies describe this as “reprioritisation”, the ISC is clear that some threats are now monitored at lower intensity as a matter of policy. Meanwhile, Russia continues grey-zone activity through cyber operations, sabotage and disinformation, testing a system still geared toward a simpler threat environment.”
Strain beneath operational success
Irwin continued: “Counter-terrorism remains effective, with 43 plots disrupted since 2017. However, the threat has shifted toward lone actors radicalised online, creating a high volume of low-signature cases. Funding constraints have delayed key technical capabilities, pushing agencies toward reactive surge management rather than proactive monitoring.
Cyber threats remain persistent despite new laws and public attributions. The ISC warns that continued activity by Russia, China and Iran suggests deterrence is either ineffective or being absorbed as a cost of doing business. Ambitions around artificial intelligence and advanced analytics sit uneasily alongside recruitment gaps and delayed programmes.”
Democratic oversight at risk
“Perhaps most troubling is the erosion of democratic oversight. Despite its expanded remit, the ISC’s staffing has been cut by over 40% and its budget reduced by nearly a quarter. With just nine full-time staff and a £1.4 million budget, the Committee argues it cannot fulfil its statutory role. Its continued embedding within the Cabinet Office further undermines independence.
“The ISC does not warn of imminent failure. Instead, it describes a system holding together through rationed effort, international partnerships and crisis-driven redeployment. But this posture is unsustainable. Risks are accumulating quietly, without open political debate about which threats the UK is prepared to tolerate at reduced coverage.
“The message is clear: without sustained investment, reform and credible oversight, Britain’s national security system risks sliding from managed vulnerability into long-term decline,”concluded Irwin.