THERESA May has threatened to use any means necessary - including "cutting-edge military resources" - to warn off Russia from further aggression as international diplomatic tensions continue to escalate.

The stronger more defiant posture from the Prime Minister towards Britain’s “enemies” coincides with a hardening of the international stance against Moscow’s culpability in the Salisbury poisoning.

Nato announced it was expelling seven diplomats from the Russian mission to the western alliance, bringing the overall expulsion number across nations and organisations to 147. More could still follow.

After Salisbury, Whitehall sources made clear Russia was now a “strategic enemy”.

READ MORE: We are at forefront of challenge to Russian threat, says RAF chief

Launching a new security review, Mrs May sets out the “Fusion Doctrine,” which means every part of government and its agencies will have a part to play in the defence of the realm.

But this “whole-of-government approach” will not only be directed against hostile states but also “organised crime groups and corrupt elites,” among whom are often cited Russian oligarchs.

Writing in the foreword to the National Security Capability Review, the PM says: “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 weapon, amounting to an unlawful use of force against the UK.”

She explains all of these incidents show Britain’s security not only relies on the police, security services and the Armed Forces but also on mobilising the nation’s “full range of capabilities…from economic levers, through cutting-edge military resources to Britain’s wider diplomatic and cultural influence on the world stage”.

Insisting that “every part of our government and every one of our agencies has its part to play,” Mrs May says Britain’s enemies "should be in no doubt that we will use every capability at our disposal to defeat them”.

Officials pointed to how soft power would be used to counter the spread of misinformation; they noted how more than 20 different stories had come out from Moscow since the Salisbury attack to "try and confuse the picture".

A senior Whitehall insider said: "It's sometimes easy to think about hard-edge direct delivery capabilities but actually, in the modern era, particularly with social media in the era of cyber space, those other capabilities, communications, some of the soft power, these are important too."

The security review includes a commitment to publish a new counter-terrorism strategy, which will include measures to improve the UK’s ability to disrupt terrorist plots in their early stages and improve frontline integration of its counter-terrorism response.

Downing Street explained the Fusion Doctrine would embed the lessons of the Chilcot report on the Iraq war by creating a more accountable system to support collective Cabinet decision-making and emphasising the importance of robust analysis, drawing on all sources of information from within and outwith Whitehall.

READ MORE: Threat from Islamist terrorism may increase, security review finds

The whole-of-government approach would “extend to serious and organised crime, including in our approach to disrupting high-harm organised crime groups and corrupt elites, a new intelligence framework, better community engagement and a National Economic Crime Centre in partnership with the private sector”.

Other measures include:

*significantly expanding the National Security Communications Team to tackle misinformation from Britain’s adversaries, making communications an integral part of the national strategy;

*strengthening the UK’s overseas network of embassies, high commissions and other missions and

*implementing the £1.9 billion National Cyber Security Strategy to ensure it keeps pace with the cyber-threat.

In Brussels, Jens Stoltenberg, the Nato Secretary General, announced the withdrawal of accreditation for seven staff at the Russian mission to the defence organisation and would refuse to accredit three more applications.

"This sends a clear message to Russia that there are costs and consequences for its unacceptable and dangerous pattern of behaviour,” he insisted.

In Moscow, Sergei Lavrov, the Foreign Minister, accused the US, which is expelling 60 Russian diplomats, of “colossal blackmail” in its pressuring of other countries to follow suit.

He claimed there were now "few independent countries" left in modern Europe.

READ MORE: We are at forefront of challenge to Russian threat, says RAF chief

At Westminster, Boris Johnson told MPs there were no plans to boycott the World Cup or to try to get a boycott by the England team, which was a “matter for the Football Association, not the Government; nor is there any desire to punish England fans”.

Responding to the SNP’s Alan Brown, who joked Scotland had "suffered a self-inflicted withdrawal" from the World Cup but noted how many Scottish fans would travel to the tournament, the Foreign Secretary stressed: "Clearly, the onus is on the Russian authorities to honour their Fifa contract in full and make sure Scottish fans, all UK fans, have a safe and enjoyable tournament."