As the war rages in Ukraine, long held assumptions in the West about Russia, about Vladimir Putin and about Russian energy have been falling like ninepins.
In their wake come admissions of guilt and acknowledgements of error.
"We failed on many points," German President Frank-Walter Steinmeier confessed this week when reflecting on his country's dependence on Russian gas.
"We should have taken the warnings of our eastern European partners more seriously, particularly regarding the time after [the Russian invasion of Crimea in] 2014," said Mr Steinmeier, who was foreign minister at the time.
True nature of Putin regime unmasked
The Kremlin’s atrocities in Bucha, Borodyanka and Irpin have meant that the anguished mea culpas can barely keep up.
Lines in the sand are drawn and redrawn, sanctions are being sharpened on the hoof, and Russian assets once deemed untouchable because of the knock-on hit to the European economy are suddenly in the firing line.
"Things that were once impossible are now possible," says one EU diplomat ruefully.
The true nature of Putin’s regime has also been unmasked, and fresh atrocities in previously occupied towns are certain to emerge. The shocking slaughter of civilians at the railway station in Kramatorsk is but the latest.
Critics say the EU's careful and graduated approach to sanctions is both a moral failure and a failure of planning.
The bestial cynicism of the Kremlin is revealed in its airy dismissals of every fresh war crime as "fake" or a "provocation". The Russian population has been gulled into credulity through a blizzard of torrid propaganda on state television. This is what the nuclear-armed superpower has become.
That propaganda is now being laced with toxic 1930s-style rhetoric. Calls for the "purification" and "re-education" of Ukrainians have been broadcast on mainstream media.
"Ukraine is an artificial anti-Russian construct that has no civilisational substance of its own, a subordinate element of an extraneous and alien civilisation," wrote a RIA Novosti columnist this week.
For those who have observed Putin’s methodical playbook since he became president in 1999, pent up anger at western naivety is out in the open.
"President Macron, how many times have you negotiated with Putin? What have you achieved?" asked the Polish prime minister Mateusz Morawiecki this week.
"Did you stop any of these actions? You do not negotiate with criminals, you fight them. Nobody negotiated with Hitler."
One diplomat remarked: "There are people who were quite sure what would happen, because they believed the intelligence on the Russian military and on President Putin and his inner circle. And they've seen the playbook in Grozny and Syria. They believe that Russia does not have any limits."
Critics say the EU’s careful and graduated approach to sanctions is both a moral failure and a failure of planning.
The executions of civilians in Bucha have certainly changed the way sanctions have been coordinated.
Before and immediately after the invasion, small clusters of EU ambassadors would hold meetings with senior European Commission officials in advance of each new sanctions package.
With the inclusion of Russian coal in the fifth package, a Rubicon has been crossed.
For obvious reasons it's a highly secretive process. Officials would let the ambassadors know - orally, nothing on paper - on a Saturday, what the Commission was proposing. They would inform their capitals and register any objections.
The following week, the new package would be on the table and EU ambassadors would go through it in detail before publication.
"There were indications of what was going to be in [the fifth sanctions package] over the weekend," says one diplomat, "but as soon as Bucha happened it was overtaken by events."
Banning Russian coal was not part of the package. It has been mooted as a later option. Nor was a ban on Russian road or sea freight entering the EU. However, by the time member states were given the draft package on Tuesday, those measures had been included.
There was consternation among Greek, Cypriot and Maltese ambassadors because the ban on Russian-flagged or owned vessels entering EU ports was going to be a bureaucratic nightmare for countries with big shipping registers.
Internal tensions have been intrinsic to the EU’s response to the invasion. Poland and the Baltic states have relentlessly pushed for tougher measures, against the more cautious approach of France, Germany and Italy.
However, with the inclusion of Russian coal in the fifth package, a Rubicon has been crossed. A more specific, but furious, debate about Russian oil and gas is now underway.
The terrible nexus of Russian energy and Russian war crimes in Ukraine is charged with high moral ultimatums and less certain economic arguments.
Breaking the link
How can Europe keep buying Russian oil and gas when those revenues directly fund Russian atrocities? That is the stark challenge laid down by Ukraine’s beleaguered government.
"If after [Bucha] the EU countries pay for Russian energy resources as usual…," Ukrainian president Volodymyr Zelensky said this week, "then the political fate of some leaders will not develop as usual. My advice to everyone: realise now that this is a really critical moment."
That Germany, in particular, understands this challenge is cold comfort for Mr Zelensky.
"The Germans admit they made a strategic mistake," says one EU diplomat.
"They became overly dependent on Russian energy. They regret it. They're trying to undo it. It will be undone. They will break the link."
But breaking the link amounts to a grand unravelling of an established order almost overnight. The German Minister for Finance told his EU counterparts in Luxembourg this week that what was required was nothing short of a new economic model for his country.
The roots of Germany’s dependency on Russian gas go way back and were not necessarily blameworthy at the outset.
Soviet Russia’s production of energy resources took off in the 1970s at a time when West Germany launched its Ostpolitik, a gradual rapprochement through trade.
"Successive German governments saw this energy partnership with Russia as something that was mutually beneficial, and therefore a stabilizing factor in Europe's relations with Russia," John Lough, an associate fellow of the Russia & Eurasia Programme at Chatham House, told a Centre for European Reform (CER) webinar this week.
That paradigm of new pipelines and cheap gas survived the Cold War and the post-Cold War era and, ultimately, fuelled Germany’s hugely successful steel and chemical industries.
While the Nord Stream 1 pipeline was bringing 160 million cubic metres of gas per day under the Baltic Sea directly into Germany from Russia, the new parallel Nord Stream 2 pipeline would have doubled that amount, delivering a combined capacity of 110 billion cubic metres per annum.
Those pipelines would cut Ukraine out of the equation, robbing it (and Poland) of valuable transit fees.
Even after the invasion of Crimea, Berlin saw merit in increasing, not decreasing, the flow of Russian gas through Nord Stream 2.
"Germany's leaders thought after 2014 they could reduce tensions with Russia by expanding this direct gaslink, even though it was going to clearly be at the expense of Ukraine," says Mr Lough.
"They thought that reducing Russia's dependence on Ukraine for the transit of gas would actually contribute to some form of stability."
German industry still fiercely defends this decades-old partnership. Martin Brudermüller, chairman of chemicals giant BASF, has described Russian gas as "the foundation of German industry's global competitiveness" and that banning it would "destroy the wellbeing of Germans".
However, while Nord Stream 2 was completed, it was one of the early casualties of EU sanctions and has not been certified. But the odds were stacked against a wholesale energy embargo at the outset.
'Everything got worse’
During an informal summit in Versailles on 5 March, EU leaders agreed on the principle that sanctions should not hurt the EU more than they hurt Russia. Energy imports would not be touched, despite the clamour from Kyiv.
"After Versailles everything got worse," says one EU diplomat.
"Now you have these war crimes and the campaign [against Russian energy] has intensified. Just because it was agreed in Versailles doesn't mean it's written in stone forever."
Olaf Scholz, the German Chancellor, has been forced into acrobatic U-turns, some of which have won him admiration abroad, given the strength of the industrial lobby, and the pro-Russia lobby on the German left, even within his own party.
While he has challenged economic experts who have said turning off gas would only mean a GDP hit of between 2% to 3%, he swiftly binned Nord Stream 2 and put Gazprom Germania, a clutch of Russo-German companies running the pipelines, into trusteeship.
German ministers now admit Russian oil, coal and gas will have to be phased out, but say without alternatives they cannot be simply abandoned overnight.
Gas is different
Russian oil brings in the biggest revenue for the Kremlin, but if the EU imposes an embargo the price of oil in Europe goes up, and Moscow can simply sell it elsewhere.
Gas is different. Europe is 35% dependent on Russian gas and gas revenues make up 15% of Russia’s budget. That percentage has risen because prices have shot up.
Gas gives the EU leverage because contracts are delivered through pipeline infrastructure that cannot simply be switched to other customers.
For Germany, cutting off the gas would either mean - depending on which expert you believe - thousands of job losses and whole communities sinking into poverty, or a shallow recession not unlike the Covid-induced one.
However, an immediate embargo would cause big problems for Russia, and not just the calamitous loss in revenues.
"Once the gas starts flowing, it has to keep flowing," says one diplomat.
"If you stop it the field starts to deteriorate and it's not easy to start again."
Europe is now desperately casting about for alternatives. The problem is that it has had only patchy investment in liquefied natural gas (LNG) storage facilities, which there are none at all in Germany.
"If Europe were to lose these imports from Russia all at once, that would basically lead to Europe facing next winter with a fairly empty storage [situation] simply because it has no alternative gas sources available," says Katja Yafimava, of the Oxford Institute for Energy Studies.
"The shortage would be so significant that it's bound to mean, particularly in Germany and Central Europe, physical gas shortages. That would mean some industries closing. That would potentially mean blackouts."
A deal with Washington
The European Commission struck a deal with Washington for - mostly fracked - US LNG to flow in greater quantities until 2030. This is an extra 15 billion cubic metres this year, rising to an extra 50 billion from next year.
This will neither compensate for the totality of Russian gas, nor is it risk-free. Joe Biden could face a backlash if American LNG flowing to Europe pushes up prices at home.
Europe gobbling up spare capacity of LNG from Gulf States could mean Asian countries being priced out of the market and being forced back to more carbon-heavy alternatives, like coal to run their power stations.
But with the carnage in Ukraine and the moral outrage of Ukrainian leadership, the EU has to act fast.
There are plans to oblige member states with LNG storage capacity to push it to 90% by November each year. There is talk of the EU procuring gas on behalf of members in the same way that it bid for Covid vaccines.
There are suggestions that wholesale buyers in Europe could refuse to pay Gazprom directly for the gas, but put the money in an escrow account until Russia withdraws its troops.
Alternatively, punitive tariffs on Russian energy exports could force member states to dramatically scale back purchases.
A tariff would be a governmental intervention and would not be a violation of the contracts. Furthermore, says Elisabetta Cornago, a senior research fellow at the Centre for European Reform, "a tax on energy imports would not stop energy from flowing…, but it would essentially eat into the rent that the Kremlin gets from the energy trade."
When it comes to gas, such a move might not escalate already high consumer prices, because Russia would have nowhere else to sell the gas and thus may have to keep prices low.
The risk is that either an escrow account approach, or even the EU sanctioning Gazprombank, which handles the transactions, would be seen by Moscow as a breach of contract and Russia would say it has no option but to turn the taps off.
In reality, Germany and Europe were going to have to scale back their consumption of Russian gas anyway in order to meet EU climate goals. Whether it is a ripping-off-the-plaster approach, or a gradual phasing out, the result will be even higher energy costs for consumers and industry, and a broader spike in inflation.
Governments remain risk-averse
Veronika Grimm, of the German Council of Economic Experts and Professor of Economic Theory, Friedrich–Alexander University says hard choices now will be even harder if left to later.
"From a security policy perspective, we have to stop Putin escalating this war," she told a German Marshall Fund webinar.
"We have to hinder Russia, we have to win this war. And this can make it necessary to take these kinds of measures."
Even though the impossible has become the possible, governments are still risk averse, and the unity the EU has displayed this far could fracture if some member states are hit harder by an energy embargo than others.
Ireland does not get gas directly from Russia, but a sudden embargo and price shock would have a knock-on effect.
According to a briefing note from the Irish Offshore Operators Association (IOOA), "Ireland would be in an extremely vulnerable situation as we have neither a direct link with the EU gas grid, nor an LNG terminal. We would be reliant on the UK (which itself is a net gas importer).
"If the UK was unable to fill its own gas import needs, is it likely that it would supply all of Ireland’s needs while not meeting the needs of its own citizens and industry, particularly in the continuing shadow of the Brexit fallout?"
An Irish official familiar with discussions agrees. "If it's a sudden stop, the price of gas will go through the roof. And then the way gas is supplier of last resort for electricity, the cost of energy in general will go up.
"Irish consumers will start to feel it quite quickly, first of all, through increased energy costs in just heating and lighting. But then the cost of fertilizers will go up because they rely on gas and that will have a knock-on effect on the price of food."
Anxieties measured against suffering
These genuine anxieties must be measured against the suffering of the Ukrainian people, and the sheer necessity that Putin’s methods and world view simply must not be allowed to prevail.
Many experts suggest that reducing energy demand must also be part of the picture. That will take a collective effort, but one which the West should and could embrace, according to Jacob Kirkegaard, a fellow non-resident with the Peterson Institute
"I am somewhat mesmerized by the unwillingness of governments…, to ask more [of their citizens], to have more concrete campaigns, ask for a consumer response, turning down the temperature in your home, and doing it by government decree in all public buildings," says Mr Kirkegaard.
"The response by the European public to this as a solidarity measure, [along] with the population in Ukraine, would be overwhelmingly well received. I certainly believe it should be tested."
The other big question which needs answering is what effect the great unravelling will have on Russia itself when it suddenly realises its biggest customer for its biggest cash resource is pulling the plug?
"Does that make it then much more dependent on the Chinese market? Is it going to foster some sort of dash for modernization in Russia itself?" asks John Lough of Chatham House.
"Ultimately, it doesn't feel like that at the moment, and it hasn't done before for many years. But this is going to have some profound consequences."
Those consequences are hostage to the staying power of western electorates and their willingness to suffer a slump in living standards and soaring energy costs in order to support Ukraine.
The sympathy and solidarity in Europe has been formidable so far, but will it last?
The outcome is hostage, too, to the horrendous dynamics of the battlefield, and to how far Putin will go to destroy Ukraine in order to satisfy his vengeance over Russia’s defeat and humiliation in the Cold War.
"This isn't over," says one western diplomat.
"It took from 2014 till 2022 for the next phase of Putin’s plan, so there will be some kind of cold version of this. And if Putin is still around, none of us can sleep. None of us can say, well, that's done."