(CNN)Europe has a long and bloody history of wars, of borders brutally contested, of nations and empires carving destructive furrows far from home. But a sad harvest of sorrow and loss after the Second World War was followed by decades of relative peace and prosperity, even during a Cold War that did not become hot.
Today that peace is being severely tested by Russian President Vladimir Putin as he masses troops on Ukraine's border and diplomats are raising the alarm in stark terms. The US ambassador to the 57 nation, globe straddling Organization for Cooperation and Security in Europe, Michael Carpenter, warned on Thursday that European security is facing a "crisis" and "the drumbeat of war is sounding loud."
Putin, whose nation buried tens of millions of its own in European wars, is unearthing fresh grievances about the post-World War peace, specifically the role of NATO, the transatlantic defensive alliance and counterpoint to Russia's predecessor, the Soviet Union.
Last summer in a 20-page document citing centuries of blood-spattered history, Putin laid claim to Ukraine, which in 1991 regained its independence following the Soviet Union's collapse, stating "Russians, Ukrainians, and Belarusians are all descendants of Ancient Rus, which was the largest state in Europe."
He concluded "our spiritual, human and civilizational ties formed for centuries have their origins in the same sources ... true sovereignty of Ukraine is possible only in partnership with Russia."
As commander of the world's fifth largest army, and barely halfway through an expected almost four-decade rule, Putin is setting the stage to stake his claim just as his ancestors did, positioning forces on Ukraine's border awaiting his command.
Having already invaded Crimea in 2014, fears Russian troops will again cross the border have never been higher.
The past week of talks -- bilaterally with the US in Geneva Monday, with NATO in Brussels Wednesday and culminating at the OSCE in Vienna on Thursday -- which were meant to ease tensions, seem to have achieved the opposite and entrenched Putin's emissaries in hostile rhetoric.
Russian Deputy Foreign Minister Sergey Ryabkov set the tone on Monday demanding "ironclad, waterproof, bulletproof, legally binding guarantees, not assurances, not safeguards, guarantees" that NATO deny Ukraine and others membership and roll back to 1997 lines.
Two days later, after NATO talks in Brussels, another deputy foreign minister, Alexander Grushko, threatened force if they don't get what they want. "We have a set of legal military-technical measures that we will apply if we feel a real threat to [our] security, and we already feel [it]," he said.
By Thursday when talks reached the OSCE, whose territory circumnavigates the northern hemisphere from Russia's easternmost frozen tundra to Alaska's icy western tip and where both Russia and Ukraine are members a diplomatic permafrost had formed. Russia's OSCE ambassador, Alexander Lukashevich, warned of "a moment of truth" with "catastrophic consequences" if Russia's "principles are violated."
In Moscow Friday, Putin's long serving Foreign Minister Sergei Lavrov warned "the West got carried away," and tapping into Russian folk law, hinted Putin's diplomacy may have run its course, saying: "We have been harnessing slowly, but now it's time for us to ride."
The same day, Ukrainians woke to a massive cyberattack taking down government websites. Russia hasn't claimed responsibility, but Europe's top diplomat Josep Borrell left little doubt who he thinks was behind the attack, saying, "It's difficult to say [who is behind it]. I can't blame anybody as I have no proof, but we can imagine."
By Russian design or the stuttering effects of stalling diplomacy, the talks are seeding spiraling consequences. Borrell promised counter measures to the cyberattack, "We are going to mobilize all our resources to help Ukraine to tackle this cyberattack. Sadly, we knew it could happen."
In the US, President Joe Biden's national security adviser Jake Sullivan on Thursday suggested Putin may have given up on talks with none scheduled in the days ahead, and on Friday the US raised the stakes further, charging that Moscow had "prepositioned a group of operatives" to execute "an operation designed to look like an attack on them or Russian-speaking people in Ukraine" to create a reason for "a potential invasion," according to Pentagon spokesperson John Kirby.
The Kremlin strenuously denied the accusation.
What happens next?
On Friday, Ukrainian President Volodymyr Zelensky invited Biden and Putin to hold three-way talks to discuss the security situation, according to Ukrainian state media outlet Ukrinform.
Lavrov has stated he believes NATO needs to make the next move, "We are waiting for answers from our colleagues, written answers, put on paper."
But Jens Stoltenberg, NATO's secretary general, told CNN on Wednesday that it's up to Russia to respond to NATO's diplomatic outreach on arms control talks and other reciprocal military agreements. "We are waiting for the answer to our proposal to convene a meeting addressing a wide range of important issues for European security," he said.
US Secretary of State Antony Blinken also indicated the US is waiting on the Russian President. "Is he going to choose the path of diplomacy and dialogue to resolve some of these problems? Or is he going to pursue confrontation and aggression?" the secretary asked Thursday.
The wait is re-awakening uncomfortable memories for Europeans. Denmark's Foreign Minister Jeppe Kofod branded Putin's actions "totally unacceptable," saying he is "trying to take us back to the coldest, darkest days of the Cold War."
But with Putin seemingly adamant he will not back down, history's shadow is pressing on the shoulders of leaders across the continent who are becoming increasingly aware that fateful decisions may lie ahead.