As chasm grows between a resurgent Russia and a divided US and Europe, diplomats say conflict is now more dangerous, with no clear rules of the road

Gen Sir Richard Shirreff remembers the moment he realised Nato was facing a new and more dangerous Russia. It was 19 March 2014, the day after Russia annexed Crimea from Ukraine.

Shirreff, then deputy supreme allied commander Europe, was at Natos military HQ in Mons, Belgium, when an American two-star general came in with the transcript of Putins speech justifying the annexation. He briefed us and said: I think this just might be a paradigm-shifting speech, and I think he might have been right, Shirreff recalled.

The Russian chairmen address aired a long listing of grievances, with the wests attempts to contain Russia in the 18 th to 20 th centuries right at the top.

Putin said: They have lied to us many times, stimulated decisions behind our backs, placed us before an accomplished fact. This happened with Natos expansion to the east, as well as the deployment of military infrastructure at our borders.

He warned that Russia would no longer tolerate such pressure: If you press the spring it will release at some phase. That is something you should remember.

Warnings of a return to cold war politics have been a staple of European debate for three years, but in recent weeks many western diplomats, politicians and analysts have come to believe the springtime has indeed been released. Russia is being reassessed across western capitals. The talk is no longer of transition to a liberal republic, but regression.

The post-cold war era is over, and a new epoch has begun. Cold war 2.0, different in character, but potentially as menacing and founded not only on competing interests but competing values.

Shows of strength such as a 2015 workout partly aimed at demonstrating Natos resolve to defend the Baltic have ruffled feathers in Moscow. Photograph: L( Phot) Luron Wright/ MoD/ Crown C/ PA

The French foreign minister, Jean-Marc Ayrault, told: The reality is that behind the appearance of consensus a form of world disorder took hold. We are now paying the price for that mistake of evaluation that devoted westerners a feeling of consolation for two decades.

In the UK, the foreign secretary, Boris Johnson, said in his party meeting speech that the west had been mistaken in its notion that the autumn of the Berlin Wall meant the world had come to a few moments of ideological resolution after seven frozen and sometimes scaring decades of communist totalitarian rule.

Others such as Sir John Sawers, the former head of MI6, advised: We are moving into an epoch that is as dangerous, if not more dangerous, as the cold war because we do not have that focus on a strategic relationship between Moscow and Washington. But unlike the cold war, there are now no clear rules of the road between the two countries.

The German foreign minister, Frank-Walter Steinmeier, an advocate of dialogue, made the same point: Its a fallacy to think that this is like the cold war. The current days are different and more dangerous.

The reasons for all this anxiety are not hard to find. The accumulation of recent Russian provocations is daunting. The hybrid frozen war in Ukraine and the bombardment of Aleppo in Syria, disclosing a determination to keep Bashar al-Assad in power, top the listing.

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