Britain would struggle to match Russian military capabilities on the battlefield and risks falling further behind potential adversaries without more investment, the head of the army will warn on Monday.
In a public speech, Chief of the General Staff Nick Carter is expected to say that Russia is building increasingly aggressive and expeditionary forces while it has already demonstrated the use of superior long-range missiles in Syria.
In 2018, Moscow initiated simulated attacks across northern Europe, from Kaliningrad to Lithuania, Carter will outline in an afternoon speech at the Royal United Services Institute (RUSI) in London.
In December, Air Chief Marshal Sir Stuart Peach said the UK should prioritise protecting undersea cables from the Kremlin, as disruption could be "potentially catastrophic" to the economy. The speech comes as national security adviser Mark Sedwill conducts a review of the UK's security capabilities.
There are concerns in the armed forces that the review will prioritise counter cyber-attacks and terrorism, rather than major defence. Last week Conservative MP Julian Lewis, chairman of the Commons defence select committee, posed an urgent question in the Commons after speculation that there were plans to cut the UK military by 14,000 service personnel, nine warships and 100 helicopters.
The warning comes after Russia practised simulated attacks across northern Europe.
In the speech, which will take place at the Royal United Services Institute on Monday, Gen Carter will highlight Russia's new cyber warfare capabilities. The Russian army conducted large scale military exercises last year, including simulated attacks across northern Europe, from Kaliningrad to Lithuania.
General Sir Nick Carter will say the British Army's ability to respond to threats "will be eroded if we don't keep up with our adversaries". The speech - approved by Defence Secretary Gavin Williamson - comes amid speculation of potential defence cuts.
He will also highlight the Russian army's long-range missile strike capability. While Russian forces were intervening in Syria, 26 missiles were deployed from a 1,500km (930 mile) range. He will add that Russia is building an increasingly aggressive expeditionary force, which already boasts capabilities the British Army would struggle to match.
Potential military threats to the UK "are now on Europe's doorstep," Gen Carter will say.
Last year Prime Minister Theresa May said Russia had "mounted a sustained campaign of cyber espionage and disruption" against other nations.
This intervention from Gen Carter is as much an appeal for more money to fund the armed forces and to avoid further cuts. Gen Carter will say the UK's ability to respond to threats will be eroded if it doesn't keep up with its adversaries, and he says the time to address these threats is now.
This appeal is being made with the approval of the defence secretary, Gavin Williamson, who's made clear he wants more cash from the Treasury.
Our assessment is that in recent months, Britain has taken an aggressive stance against Russia. On November 2017, in a rare move, UK Prime Minister Theresa May launched her strongest attack against Russia by accusing the nation of meddling in elections and planting fake stories in the media and condemned Russia’s alleged attempts to “weaponise information” in order to sow discord in the west. General Carter’s warning further signals that Western democracies now view Russia and the government as a direct threat to their sovereignty.
On its own, UK will not be able to match Russia’s arsenal. That's why it is part of NATO. But even as a key member of the alliance, some of the UK's weapons are increasingly outdated. While Russia's been developing new Armata tanks, the British Army's Challenger 2 hasn't been modernised for 20 years. We believe that General Carter's intervention is more driven by fears of further deep cuts to the UK's armed forces.