Secret "Russian subs" off Sweden, tit-for-tat sanctions, NATO fighters scrambling to intercept Russian warplanes: relations between the West and Moscow over Ukraine have sparked incidents reminiscent of the Cold War that terrified the world for decades.

Even Cold War doyen Mikhail Gorbachev used the highly symbolic 25th anniversary of the fall of the Berlin Wall to warn the world was "on the brink of a new Cold War", adding that "some are even saying that it has already begun".

And it's not just former leaders. Finland's Prime Minister Alexander Stubb also sounded the alarm, saying that Russia's actions over Ukraine were bringing the world to the "brink of a Cold War."

But while experts agree that the current situation is extremely dangerous, they say it is very different to when the two nuclear-armed superpowers faced off, seemingly only minutes away from all-out global destruction.

Instead of a Cold War, experts see a period of geopolitical rebalancing after years of the United States assuming the role of sole superpower.

"Saying that we're in a Cold War is to misunderstand the situation," says Vladimir Evseev, director of the Moscow-based think-tank NCO Public Political Studies Center.

"This isn't a Cold War, but a period of transition. Western domination is coming to an end. The West can no longer impose its will on the world," added the expert.

- 'Expansionist, ideological power' -

Several factors in the current tension between Washington and Moscow differ from the terrifying limbo that existed between the superpowers until the Berlin Wall fell in 1989, experts say.

Firstly, the Cold War was more than a conflict between two competing superpowers, it was a battle of ideology, a battle of ideas, which simply no longer exists, Evseev told AFP.

"There are ideological differences, but the Iron Curtain no longer exists and it cannot exist in our time."

Quite simply, as unpalatable as Vladimir Putin's Russia is to the West at the moment, it is a long way from being the Soviet Union that antagonised Washington and Europe for decades.

"The Soviet Union was an expansionist, ideological power with global ambitions and deep hostility to Western interests," wrote analysts Samuel Charap and Jeremy Shapiro in a recent commentary in Current History.

"Post-Soviet Russia is unpleasant, and has transgressed a number of key international norms in the past year, but it is not the Soviet Union."

Seismic changes have also taken place politically and economically since the collapse of the Iron Curtain, making it impossible to talk of a re-run of the Cold War.

Despite sanctions over Ukraine, the Russian and Western economies are deeply intertwined and politically, Moscow and the West work together on several other thorny issues, notably on preventing Iran acquiring a nuclear bomb.

"The most important difference today is the factor of China," said Sergey Radchenko, an expert on Russia and the Cold War at Britain's Aberystwyth University.

"Today, China is the greatest assurance Russia has that it will not be isolated, neither politically nor economically. The difference is great, and the gist of it is that the West will find it a lot more difficult to deter Russia through a show of force," Radchenko told AFP.

- 'Cold peace' -

So what do we have if not a Cold War? Camille Grand from the Paris-based Foundation for Strategic Research says he prefers the term "Cold Peace".

"We're in a new post-Cold War architecture where the idea that cooperation is the natural way of dealing with Russia is no longer valid," he told AFP.

"In the long term, Russia does not have the means to be a superpower. That is a sort of illusion to please the Russian people."

The West has to realise that it has entered a new period in geopolitics and "stop wasting our time hoping it will go back to normal," said the analyst.

However, Radchenko points out one similarity with that period in history: the conflict in Ukraine is being "pursued through proxies".

"In this sense, what we are seeing in East-West relations today is a replay of the Cold War -- yes, on a smaller scale but with equally dangerous possibilities of escalation."