A year since Vladimir Putin shocked Europe by annexing Crimea and fomenting rebellion in Ukraine’s previously quiet Donbas region, his undeclared war on the Russians’ east Slav brothers has become the “new-old normal” on the continent. It has displaced the seven-decade interlude in which Europeans thought they had established a postmodern order of peace in their heartland. It has induced a loss of hope that Europe’s embodiment of the liberal peace first envisioned by Immanuel Kant can be restored within less than one or two generations – if at all. It has confronted the west with a stark choice between appeasement of a regional bully or war with no mutually understood restraints in a nuclear-armed world.

Already the truce hammered out by the Ukrainian, Russian, German and French leaders on 12 February in all-night negotiations held in Minsk, Belarus, has collapsed in reality, if not in name. Separatists in eastern Ukraine and their allied Russian “paid volunteers” never halted their saturation shelling of the town of Debaltseve at one minute past midnight on 15 February, as had been agreed, but kept up the barrage for three and a half more days until the thousands of Ukrainian soldiers surrounded there died, or were captured, or managed to retreat under blistering fire to contiguous Ukrainian territory.

Only a few of the heavy weapons that were supposed to begin being withdrawn from the designated buffer zone on 16 February have been pulled back on either side. The rebels have not allowed international monitors to take up their designated posts in the ceasefire zone and on the Russian-controlled Ukrainian border.

The truce that was patched up again after the destruction of Debaltseve will probably provide no more than a brief winter respite before a spring offensive by rebels and Russian professional soldiers in eastern Ukraine. Moscow still denies that any of its troops and modern heavy weapons are there, despite all the direct photographic, electronic and eyewitness evidence of their presence and the indirect evidence of artillery and multiple-rocket-shell targeting on Debaltseve with a precision that only well-trained Russian crews could provide. Since fighting began last April, nearly 5,700 people have died and 1.5 million have fled their homes, according to the United Nations.

Even before the ceasefire that never was, the German chancellor, Angela Merkel, provided the epitaph for European peace by warning that she could see no realistic scenario in which any arms the west might give Ukraine would significantly change the balance of power in the conflict. Russia cares more about the fortunes of Ukraine than any other outside country, and possesses the military strength, resources and capability to counter any new weapons that Ukraine may be gifted. The only hope Merkel could offer was that, with strategic patience, the west might eventually triumph, just as it ended the cold war – in tandem with the unmentioned Soviet statesman Mikhail Gorbachev – with the bloodless fall of the 28-year-old Berlin Wall in 1989.

This dark prognosis has been reached only in recent weeks. Throughout 2014, Europeans still hoped that their accustomed order could be restored soon. As Russian special forces in unmarked uniforms and masks abruptly ended the quarter-century of amicable coexistence of the Russian and Ukrainian fleets in their Crimean port and deposed the peninsula’s regional government at gunpoint last March, the US president, Barack Obama, dismissed post-superpower Russia as little more than a regional nuisance.

Chancellor Merkel took Putin’s irredentist threat far more seriously. She warned the US president that his Russian counterpart was living “in another world” of tsarist-era nationalism that, she implied, precluded any cost-benefit rationality or compromise. Obama, preoccupied with pullback from America’s overstretch in the Middle East and Afghanistan and his so-called pivot to Asia, in effect outsourced second-rank diplomacy about Ukraine to Berlin. For the first time since 1945, Germany had thrust upon it a geopolitical leadership of Europe commensurate with the country’s economic clout. And for the first time Merkel, whose hallmark had been leading from behind, stepped out in front.

As Putin raced towards annexing Crimea, Merkel told the Bundestag on 13 March 2014 that the previous 69 years of reconciliation, peace and freedom that had been created by an integrating Europe and the transatlantic democratic alliance were a feat that “can still be considered a miracle”. Russia’s theft of Ukrainian territory was unacceptable in 21st-century Europe and represented a reversion to the law of the jungle and to “the law of the strong against the strength of the law”, Merkel said.

She reprimanded Russia for violating international law and specific treaties to which Moscow was a party, including the 1975 Helsinki ban on changing European borders by force and Russia’s 1994 assurance of Ukrainian independence, sovereignty and borders in return for Kyiv’s surrender of its huge arsenal of inherited Soviet nuclear weapons to Moscow.

In dozens of phone calls she warned a disbelieving Putin that Europe’s hard-won peace trumped commercial interests and that this time he could not count on Germany’s pro-Russian business lobby to veto economic retaliation for his provocation. Europe and the US announced that they would not intervene militarily to defend Ukraine, a non-member of Nato, but would gamble instead on countering Russia with slow-impact financial sanctions on his entourage.

Roses on an army tank in Hrashevatoe, eastern Ukraine, abandoned by Ukrainian troops fleeing the Russian onslaught. Photo: Larry Towell/Magnum Photos

Merkel was the west’s logical interface with the Russian president. She was the ultimate Putin-Versteher, or “Putin understander”, not in line with the original coinage of this euphemism to describe German apologists for Putin, but in the sense of someone who grew up in Communist East Germany, spoke Russian and sensed the Russian mindset intuitively.

She understood Putin’s paranoia about being encircled by Nato, even if that alliance has expanded not by armed seizure of neighbours’ territory but by responding to the clamour for membership by central Europeans fearing Russian recidivism to Soviet-style forced hegemony. She comprehended the threat to his own rule that Putin feared from street protests in Kyiv; he had served as a KGB recruiter of spies in East Germany in the 1980s and watched the Berlin Wall fall to people power.

Merkel also grasped his resentment at the subsequent Soviet collapse that he calls the 20th century’s “greatest geopolitical catastrophe” – and at the independent Ukraine that emerged from the Soviet Union and illicitly tempted its people, in his view, to betray their elder brother Russians by no longer obeying them as tradition required. The humiliation he felt over the cumulative shrinkage of his influence in Ukraine was well known in Berlin.

Putin first lost all of Ukraine when his protégé Viktor Yanukovych, then president of Ukraine, allowed police snipers to murder scores of pro-European, pro-democracy

“Euromaidan” protesters a year ago. The violence alienated even Yanukovych’s own party and left him no choice but to abscond to exile in Russia, thus ensuring that Ukraine would not add its Slavic weight to Putin’s pet “Eurasian Economic Union” project. Putin’s insistence that Kyiv join the newborn Union, sometimes called “the Soviet Union lite”, was the original spark for the Euromaidan demonstrations in late 2013.

Putin next lost Novorossiya, as he anachronistically called the eastern third of today’s Ukraine that he suddenly claimed for Russia. (The term dates back to the time of Catherine the Great, who seized “New Russia” from the Ottoman empire in the 1780s.) He seemed to believe his own propaganda that discontented Russian speakers in the region would rise up if Russian special forces ignited a rebellion there.

Yet the masses failed to revolt. Only in the rust belt of the Donbas could Russian proxies mobilise ill-paid retirees and buy or coerce enough additional support to set up the self-proclaimed People’s Republics of Donetsk and Luhansk. Indeed, in the east of Ukraine as a whole, where many made no clear distinction between Russian and Ukrainian ethnicity, opinion polls showed that most people favoured staying within the Ukrainian state.

Merkel understood that Moscow’s cost-free takeover of Crimea in the name of restoring Russia’s lost greatness – the greatly outgunned Ukrainian army on the peninsula did not resist the regional coup, and no Russian blood was shed – was boosting Putin’s popularity ratings to more than 80 per cent. This gave him renewed domestic legitimation even as his decade-old social contract of restoring order and offering a better life to a new, urban middle class in post-Soviet Russia was becoming ineffectual at a time of economic slowdown.

Merkel therefore did not expect the Russian leader to budge from his zero-sum view of international relations. Nor did she expect to deflect him from his reversion to Russia’s historic sense of victimhood and need for a security so absolute that Moscow required the insecurity of neighbours in its sphere of influence.

She did, however, see Putin as an improvising tactician rather than a single-minded strategist. This made him unpredictable, but it also allowed for movement.

At the first stage of the Ukraine crisis Merkel repeatedly offered to help Putin save face if he would cease his depredations, to the point of suggesting European Union-Eurasian Union talks about creating a common economic space. She hoped to keep him talking rather than shooting for as long as possible and to nudge him towards a more realistic perception of the advantages he was losing and the tactical costs that he was incurring in his drive to punish both the Ukrainians and the west for its treatment of Russia as a second-class power.

Merkel first prepared the domestic foundation to support her diplomacy. She forged a close policy partnership with her Social Democratic foreign minister, Frank-Walter Steinmeier. He and others in his SPD parliamentary caucus weaned the Social Democrats from their romantic nostalgia for the old Ostpolitik days of Chancellor Willy Brandt. Together, the grand coalition between the SPD and her own conservatives gave Merkel an 80 per cent majority in the Bundestag in support of targeted sanctions against Russia.

The chancellor then rallied German business to the cause of sanctions – well before the shooting down of a Malaysian passenger airliner over rebel Ukrainian territory last July, an event that is commonly credited with causing a change of heart among Germany’s pro-Russian elite.

Finally, Merkel took the sacrifices that German importers and exporters were ready to make (the huge trade between Russia and Germany shrank by one-fifth between 2013 and 2014) to her EU partners. She argued that the French should make their own sacrifices by not delivering two Mistral-class helicopter carriers they had contracted to sell to the Russians, and that the British should enforce their money laundering laws in dealing with the many Russian tycoons who have made a second home in London.

In the end, Merkel delivered the unanimous vote of all 28 EU members that was required to approve sanctions; and she saw to it that the authorisation was written with enough flexibility to add names to the target list and subtract others without making every shift subject to a new vote of unanimity. It was a quiet tour de force.

However, one task the chancellor did not take on was persuading the generally Russophile German public that Putin’s behaviour was unacceptable. That did not matter, because foreign policy remains an elite exercise in Germany – and because the Malaysia Airlines tragedy did alter popular perceptions of the Russians and yield 70 per cent public approval of sanctions.

In mid-April last year, Merkel initiated a brief Geneva agreement that put on paper a basic wish-list: stopping the violence, disarming illegal armed groups, returning seized buildings to their rightful owners and giving international observers from the Organisation for Security and Co-operation in Europe a monitoring role in eastern Ukraine. By bringing the Russian foreign minister, Sergey Lavrov, and his Ukrainian counterpart together at the same table, the Geneva accord also finessed Moscow’s tacit recognition of the legitimacy of the interim Ukrainian government (appointed by parliament after Yanukovych fled), which Russian propaganda was presenting as the illegitimate result of a fascist coup.

Ironically, the west was aided by the weakness of the provisional Ukrainian government. Over five weeks in April and May, Putin mounted menacing war games by placing up to 80,000 Russian troops on high alert on Ukraine’s northern, eastern and southern borders. But he did not need to invade in order to extend his influence. Local mercenaries, criminal gangs and other proxies under the command of special Russian forces were occupying administrative buildings in a string of medium-sized towns in eastern Ukraine. Putin presumably thought he could control whichever leading politicians emerged in Kyiv without having to shed Russian blood. In this decision he displayed tactical caution, preferring the weapon of intimidation to that of military occupation, with its risks of quagmire and even guerrilla resistance.

The next phase of the Ukraine crisis began in late May with the unexpected landslide election as president of Petro Poroshenko, the “chocolate king” oligarch who

built his confectionery empire in the 1990s after the collapse of the Soviet Union, and who also has construction and media businesses. Poroshenko had served in several crony governments and was briefly trade minister under Yanukovych. But he had been a strong backer of the Orange Revolution, which began in 2004, sparked by elections rigged in favour of Yanukovych. He also supported the Euromaidan demonstrations from the beginning.

Poroshenko quickly sent the Ukrainian army and militias on an “anti-terror” counteroffensive to recover territory lost to the rebels and their Russian special forces allies. In April the long-neglected and underfunded army had failed miserably in the same mission, in part because hardly any soldiers had such simple protection as Kevlar vests or night-vision goggles, and also because the Ukrainians couldn’t believe that they must shoot at brother Russians who were shooting at them. There were defections to the pro-Russian side.

By the summer, however, older Ukrainian soldiers who had once served in the Soviet army helped the ragtag Ukrainian forces and the better-equipped militias to get their act together. They gradually recovered most of the territory held by the rebels and by mid-July were besieging the remaining rebel strongholds in the cities of Donetsk and Luhansk. In Kyiv, hopes rose that the Ukrainians could prevent further dismemberment of their country.

On the rebel side, Colonel Igor Strelkov, the designated Russian military intelligence commander of the local proxies and mercenaries who were being pushed back, complained bitterly that they were being deserted by the leadership in Moscow and asked for more heavy weapons. The Russians obliged by rolling over the border into the Donbas more multiple rocket launchers, anti-aircraft missile systems, plentiful ammunition and the powerful ground-to-air Buk missile system, which can reach an altitude of 10,000 metres.

In late August the first known direct invasion of eastern Ukraine by Russian paratrooper units followed, rolling back the Ukrainian sieges and delivering Putin’s clear message that he would not let his proxies in the Donbas be defeated. Some, perhaps all, of the Russian airborne troops returned to their home bases after their punitive raid.

Poroshenko understood Putin’s line in the sand instantly and, on 5 September, he agreed through an envoy to a truce with rebel leaders that made the half of the Donetsk and Luhansk regions then under rebel control a no-go zone for Ukrainian troops. The ceasefire was never fully observed but it de-escalated the fighting to low-intensity shelling, and the front line remained relatively stable for four months.

German diplomacy in this interlude consisted of trying to freeze the conflict by converting the September truce and subsequent protocol into a permanent, comprehensive ceasefire, or at least into an acceptance of common constraints on escalation. The fear was that if that could not be agreed on, Europe would enter an era of acute Russian-western hostility without even the mutual restraints that the two superpowers settled on at the height of the cold war.

Menacingly, Putin boasted that his troops could be in Kyiv within two days if he so ordered; and could reach the capitals of Estonia, Latvia, Lithuania, Poland and Romania, all Nato member states, just as fast. Indeed, he has been illustrating the point graphically by aggressively testing Nato defences of the Baltic and Atlantic states daily on the seas and in the air – and endangering passenger flights by sending bombers with their transponders turned off into airspace that civilian liners use. On 18 February, RAF jets were scrambled after two Russian military aircraft were spotted off the coast of Cornwall.

The debacle of this month’s attempt to secure a truce has killed the last residual hope of a swift peace. Clearly, the end of the neo-cold war will not occur the way its superpower original did a quarter-century ago, when Washington ostentatiously outspent and out-innovated Moscow in weapons as well as general prosperity just as the Soviet economy and society reached a dead end, making Mikhail Gorbachev decide to trade in empire and feud in return for soft power and animal spirits.

Nor will it come alone from Angela Merkel’s strategic patience, which Philip Stephens of the Financial Times parses as long on patience but short on strategy. And it is unlikely to stem from Vladimir Putin’s progressive foreclosure of his own options by doubling down militarily after every failure to persuade non-Russians of the splendours of Great Russian hegemony. The only certainty is that the war between Russia and Ukraine will go on.

Elizabeth Pond is a journalist based in Berlin and the author of several books about Germany, Europe and the Balkans. They include “Beyond the Wall: Germany’s Road to Unification” (Brookings Institution)