UK in ‘new era of national security’ as AI supercharges rising threats, security chief warns

MI5 is the United Kingdom’s domestic security service. Its role is to identify and counter threats inside the country, including terrorism and hostile state activity. It protects national security by investigating dangers before they cause greater harm and by helping the country remain resilient and vigilant.

The article describes MI5 handling threats such as arson, sabotage, cyber-attacks, coercion, violence, espionage, and terrorist planning. Its work also includes responding to activity linked to Russia, Iran, and China. These threats can target communities, infrastructure, military sites, companies, or government interests.

MI5’s responsibilities are expanding. Its terrorism and state-threat missions are now roughly equal in scale. McCallum said MI5 is devoting more resources to state threats in 2026 than during the Cold War, while its state-threat caseload has quadrupled over the past decade. Terrorism remains a top concern, and an attack is considered highly likely.

Hybrid warfare is a broad campaign that combines different kinds of pressure against a country. It can use digital attacks, physical sabotage, intimidation, arson, violence, espionage, or criminal proxies. The aim is to create disruption and fear while making responsibility harder to prove or respond to directly.

The article gives Russia as the clearest example. It mentions a cyber-attack on Polish energy infrastructure and an alleged attempt to use an explosive-laden drone to destroy a cargo plane in Germany. In Britain, a man was charged with allegedly preparing to sabotage a drone factory in Swindon. These actions combine technology, physical damage, and covert operations.

Iran is also accused of using similar methods. More than 50 people have been arrested in connection with Iran-linked plots, mostly involving British Jewish communities. The article says hybrid warfare is growing across Europe and is not a temporary problem. Security services must therefore track many connected forms of hostile activity.

MI5’s state-threat caseload has quadrupled over the last decade. That growth marks a major change in Britain’s security priorities. Ken McCallum said the country has entered a new national-security era, replacing the relative stability associated with the post-Cold War years.

The comparison with the Cold War is especially striking. McCallum said that in 2026, MI5 is devoting more resources to countering state threats than it did during the Cold War. He also said terrorism and state-threat operational missions are now roughly equal in scale. The main state threats identified are connected to Russia, Iran, and China.

This does not mean terrorism has disappeared. MI5 still considers terrorism a top concern, and an attack is highly likely. Instead, the service is dealing with two large areas at once. The broader caseload includes espionage, cyber-attacks, sabotage, coercion, violence, and suspected plots directed by foreign states.

Artificial intelligence can make hostile operations faster, cheaper, and more capable. The article says AI is already supercharging some threats, especially in cybersecurity. It could help attackers discover weaknesses, automate parts of an operation, or produce convincing material for deception and coercion. These possibilities increase pressure on defenders.

The article also identifies a more serious biological danger. AI has the potential to help make destructive bioweapons, although this has not yet happened. The same technology could strengthen terrorism or espionage by giving operators better planning, analysis, or communication tools. The source does not provide specific examples of AI-enabled terrorist or espionage operations.

The central concern is capability spreading beyond highly advanced organizations. McCallum warned that comparatively low-sophistication actors could receive a capability uplift in the AI era. Governments therefore need effective guardrails. MI5 has announced a new AI Threat Assessment Center to study these risks and prepare for their possible expansion.

The three countries are identified as major threats because Britain’s security service sees their activity as part of a growing state-threat caseload. The alleged methods include espionage, cyber-attacks, sabotage, coercion, violence, and plots against communities or military-related targets. Their campaigns can operate through intermediaries rather than openly declared state action.

Russia is described as “aggressor number one.” Examples include a cyber-attack on Polish energy infrastructure, an alleged explosive-drone attempt against a German cargo plane, and a suspected plan to sabotage a drone factory in Swindon. Iran is linked to more than 50 arrests, mostly involving plots against British Jewish communities, and to ambitions involving harder targets such as military sites.

China is accused of conducting espionage in the UK. McCallum referred to an MI5 alert for academics and convictions connected to Beijing. Russia’s foreign espionage capacity has weakened after more than 1,000 staff were expelled, so it has allegedly paid criminals to act for it. The article says Iran has used similar methods.

AI can lower the skill barrier for dangerous operations. A person or group with limited technical ability may use AI to perform tasks that previously demanded specialist knowledge, extensive time, or large resources. This is why McCallum warned of a capability uplift for comparatively low-sophistication actors.

The article gives cybersecurity as the clearest area where AI is already supercharging threats. It does not describe a specific AI-enabled attack, but the mechanism is clear: AI can increase an actor’s ability to organize or conduct harmful activity. The same concern extends to terrorism, espionage, and the possible development of destructive bioweapons.

This change could widen the pool of people able to attempt serious operations. It may also make existing threats harder to predict and stop. McCallum called for governments to create effective guardrails around AI. MI5’s new AI Threat Assessment Center is intended to assess these emerging dangers, although the article gives no further details about its structure.

The post-Cold War years are presented as a period of relative stability. Britain is now entering a “more contested era,” marked by growing pressure from hostile states and continuing terrorism. McCallum said the heightened environment is not a temporary blip, and state threats have grown beyond Cold War levels in MI5’s current workload.

State threats often involve espionage, cyber-attacks, sabotage, coercion, and influence carried out through foreign networks or criminal proxies. Terrorism presents a different danger because it seeks to cause an attack, and MI5 says one is highly likely. The article’s examples show why the security service must track both covert state campaigns and violent extremist threats.

The article does not specify detailed countermeasures for each category. It does emphasize resilience, vigilance, effective AI guardrails, and continued MI5 operations. The equal scale of terrorism and state-threat missions means Britain must maintain both kinds of protection while adapting to technology that can strengthen either threat.