“We have seen much greater Russian aggression this year, and in previous years, in terms of long-range aviation, in terms of submarine activity, and the carrier task group that sailed through our waters, the role of Russia in Syria and elsewhere,” he told the Defence Select Committee.
Asked if Britain would have the Army capability for any war with Russia in 2018, or 2019, Sir Michael said: “Yes, we would be ready to increase the tempo in that kind of situation, which I don’t immediately foresee.
“And, of course, we will not be doing this on our own.
“We will be doing this as an active member of Nato, and presumably in some kind of Nato scenario.”
It was ‘too extreme’ to claim that ‘war with Russia is likely next year’, he added.
Sir Michael hoped sending 800 British troops to Estonia would deter aggression in Baltic states that were part of the Soviet Union.
“The whole point of forward deployment to Estonia is to arrange ... an earlier tripwire so the force there doesn’t have to wait for tension to escalate,” he told MPs.
“The force will be there from next spring in any event, in all three of the Baltic states.
“It’s partly reassurance, but it’s also deterrence - to make it very clear to any potential aggressor that Nato is ready to respond.”
Meanwhile, Chancellor Philip Hammond warned that ‘rogue states’ were trying to target UK infrastructure such as power grids and air traffic control.
His comments came after MI5 director general Andrew Parker warned that Russia ‘is using its whole range of state organs and powers to push its foreign policy abroad in increasingly aggressive ways - involving propaganda, espionage, subversion and cyber-attacks’.
Without naming Russia, the Chancellor highlighted attacks on French broadcaster TV5 Monde and Ukraine’s power grid - both of which security experts have suggested were carried out by Moscow-backed hackers.
Britain ‘must now keep up with the scale and pace of the threats we face’, including those carried out by foreign agents who then try to deny their involvement, said Mr Hammond, as he launched the Government’s new national cyber security strategy.
“The ability to detect, trace and retaliate in kind is likely to be the best deterrent,” Mr Hammond added.
“We will not only defend ourselves in cyberspace, we will strike back in kind when we are attacked.”