Britain faces at least two more years of heightened terror alert, with risks from state players including Russia as well as the aftermath of the collapse of Islamic State, Whitehall sources have said.

Speaking as the government launched its national securitycapability review, the sources said the risk level – currently at severe – could soon rise to critical, thanks to the possible return of scores of Isis fighters to the UK and the potential threat from states such as Russia, North Korea and Iran. Instability in north Africa, Yemen, Sudan and Syria were also said to be causes of concern.

Unveiling a “fusion doctrine” for tackling national security threats, the prime minister says in the foreword of the review that every part of government and its agencies will have a part to play.

“Over the past year in the UK we have witnessed appalling terrorist attacks in London and Manchester, but also a brazen and reckless act of aggression on the streets of Salisbury: attempted murder using an illegal chemical weapons, amounting to an unlawful use of force against the UK,” Theresa May says.

The review was partly a response to last year’s attacks. The Salisbury poisoning came too late to be considered, although sources believe the way it has been handled justifies the approach the review sets out.

But the capability review fails to meet any of the criticisms made by parliament’s joint committee on national security, published late last week.



MPs and peers on the committee, including former foreign and defence secretaries of both main parties, were strongly critical of the lack of additional money. In January, the National Audit Office identified a potential £20bn shortfall in the defence budget, and the national security review was conducted on the basis that there would be no significant increase in the £56bn budget. The committee’s report warned that “financial constraints are distorting the UK’s national security”.

The review also fails to answer the committee’s criticism of the decision to separate reviews of national security capability from strategic defence. The MPs warned that the separate defence review announced in January meant the review of national security capability had become an uncomfortable “halfway house” between a “quick refresh” of capabilities and a full review.



The committee argued that defence and national security strategy cannot be separated. Its report said reviews should be a “joined-up process led by the Cabinet Office” and called for a detailed description of how coherence between the modernising defence programme and domestic security, cyber and modern deterrence can be ensured.

The fusion doctrine is meant to embed recommendations made in the 2016 Chilcot report into the Iraq war, which called for a more accountable system to support collective cabinet decision-making after ministers failed to effectively challenge claims there was an imminent threat from weapons of mass destruction.

Senior Whitehall officials believe the way the Salisbury attack was handled has shown that the threat from a “more aggressive” Russia was correctly assessed and proved the value of cross-government working.

The response to the attack was both quicker than it had been when the Russian exile Alexander Litvinenko was poisoned more than a decade ago, and more coordinated. It brought together the diplomatic network, communications and law enforcement.

Some of the details of the process that led to this week’s coordinated response to the Russian attack and the expulsion of more than 100 “intelligence diplomats” from scores of countries are now becoming clear.

The UK shared “unprecedented” amounts of intelligence to allies in the EU and Nato in order to persuade them of Britain’s case that there was no plausible alternative to Russian responsibility.

That intelligence is believed to include evidence that Russia had been working on the nerve agent novichok despite failing to report it to the Organisation for the Prohibition of Chemical Weapons, and on systems that would allow it to be used for assassinations.

May also uses the review’s foreword to hail the development of social media to tackle misinformation. A new national security unit to tackle fake news was announced in January. The Foreign Office and the Russian embassy have been engaged in a prolonged Twitter war since the Salisbury attack as they try to establish rival narratives. The FCO has made short videos targeting under-25s to counter Russian disinformation.