Britain would struggle to match Russia's military capabilities on the battlefield, Chief of the General Staff Nick Carter has said in a speech.
In a Jan. 22 address to the Royal United Services Institute, a British defense and security think tank, Carter said Russia is building an increasingly aggressive expeditionary force while already demonstrating its use of superior long-range missiles in Syria.
The speech -- approved by Defense Secretary Gavin Williamson -- warned that Britain risks falling further behind potential adversaries unless it increases investments in its military operations.
Williamson has made it clear that he wants more funding for the NATO country's military.
British Royal Marines, Greek Marines and The Marines with Black Sea Rotational Force 17.2 talk about enemy engagement tactics during force integration training at Maleme Airport Crete, Greece Nov. 18, 2017. U.S. Marines and Greek Marines participated in Exercise Blue Raptor, an exercise involving United States, British, and Greek military to improve interoperability and to promote stability throughout the region. (U.S. Marine Corps photo by Sgt. Brandon Thomas)
"The threats we face are not thousands of miles away but are now on Europe's doorstep," Carter said. "We have seen how cyberwarfare can be both waged on the battlefield and to disrupt normal people's lives."
Prime Minister Theresa May said last year that Russia had "mounted a sustained campaign of cyberespionage and disruption" against other countries.
"The time to address these threats is now -- we cannot afford to sit back," Carter said.
"Our ability to preempt or respond to threats will be eroded if we don't keep up with our adversaries.
"We must take notice of what is going on around us or our ability to take action will be massively constrained.
"Speed of decision-making, speed of deployment, and modern capability are essential if we wish to provide realistic deterrence."
The head of the air force, Air Chief Marshal Stuart Peach, has also warned that Russia is an increasing threat.
Britain's defense spending has been hit hard by government-ordered austerity following the 2008 financial crisis.
Reports have suggested the government is contemplating combining elite units of paratroopers and the Royal Marines as part of plan to reduce the number of military personnel by 14,000. That would represent a 10 percent reduction from the current staffing level of 137,000.