NATO keeps insisting it is not in, and does not want, another Cold War with Russia.
But Britain’s former Ambassador to Russia, Sir Tony Brenton, has just told me "what it looks like is going on is just like during the Cold War".
Or to put it another way, if it looks like a duck, swims like a duck, and quacks like a duck then it's probably a duck.
Russian President Vladimir Putin
But agonising about whether the posturing between Russia and NATO meets a definition of Cold War is probably a pointless exercise.
What matters is trying to break the tit-for-tat cycle that the Western alliance and the old Soviet master seem to be locked in.
When NATO demonstrates its military might, Russia does something like send a Kilo-class submarine (pictured above) to the English Channel, or buzz a US warship in the Baltic.
And NATO responds with declarations and exercises designed to show that it will defend its members.
Last year 36,000 troops took part in the largest NATO exercise in over a decade, Exercise Trident Juncture
Countries like Poland, Estonia, Latvia, and Lithuania are worried that they may be the next former Soviet state in Russia’s sights - that like Ukraine, they could find 'little green men' (Russian troops) on their soil.
It’s not just the occasional submarine and plane that worry them. Russia says it's planning three new army divisions to be stationed along its border with Europe.
In turn, NATO is expected to announce a big uplift of alliance troops and equipment in Eastern Europe, at its summit in Poland in a few weeks.
Both accuse the other of sabre rattling. Conservative MP Johnny Mercer, who sits on the Commons Defence Committee, says:
"I think the key difference is NATO is very clearly a defensive organisation. Russia has clearly proved itself in the last 24 months to not be that, and where those two philosophies collide is where you’re going to get problems."
This week, exactly five years ago, a Russian submarine was in the Mediterranean during a NATO exercise. It wasn’t there to spy on the manoeuvres - it was invited to take part in them.
Forces News was even invited to film on board, the first foreign media to do so.
It was a show of what was meant to be a new era for NATO and Russia, friends rather than enemies, co-operating rather than fighting.
A Russian submariner taking part in NATO Exercise Bold Monarch 2011
It was no ‘bromance’, there were still some major differences, but back then the NATO-Russia Council used to meet regularly to discuss and work through worries.
In the last two years that group has met just once.
History suggests that talking will be the only way out of the military tit-for-tat cycle, but it often requires one side to break that cycle first as a symbolic move.
Former Moscow Ambassador Sir Tony Brenton believes NATO is best placed for that move. He says:
"They [Russia] feel threatened by NATO, it’s worth recalling, just as we feel a bit threatened by them. We are overwhelmingly the strongest of the two parties in this… so Russia against NATO is a bit like Australia against China."
"We should be finding ways of opening channels to the Russians, reassuring them… and trying to get the tension down”
A military cycle like this cannot go on forever and neither side will want a Cold War on the scale of the 20th century. Among other reasons, they really can't afford it.
It’s a bit like a staring game though. Neither side wants to blink first, and when it does finally come to negotiating a way out of the cycle both sides will want to do it from a position of military strength.