Europe's leaders are meant to convene in solemn mood in Ypres on Thursday evening as they mark the centenary of the outbreak of the first world war in a ceremony at the Menin Gate.
The atmosphere during a subsequent dinner at the medieval Cloth Hall in Ypres may, however, not quite match the occasion as Britain finds itself in a minority of two – and possibly just one – over the expected appointment of Jean-Claude Juncker as president of the European commission.
If, as now seems likely, a vote is held among the EU's 28 leaders on the European council on Friday afternoon in Brussels, the subsequent emphatic defeat for Britain will be remembered as a landmark event in Britain's tortured 41-year membership of the EU.
David Cameron, who became the first British prime minister to veto a EU treaty in 2011, will once again have staged a major showdown at a Brussels summit, only to lose.
Elmar Brok, the veteran German CDU MEP, believes the prime minister appears not to have learnt a lesson that the EU is evolving away from the era of national vetoes. "There's no veto principle any more," said Brok. "It's majority voting. Everyone's trying to get a consensus, but the way to get that is to ask what is the price of getting the UK to move towards Juncker. The point is what is possible."
The sight of Cameron adopting a confrontational approach towards fellow EU leaders, in the full knowledge of defeat, is alarming pro-Europeans who fear the appointment of Juncker in such circumstances will take the UK a decisive step towards the EU exit door.
"That is what it looks like," Britain's veteran former ambassador to the EU Lord Kerr of Kinlochard told the Guardian. "I dread to think what he will say as the European council ends."
The row over Juncker also raises questions about the prime minister's fundamental calculation in the negotiations he plans to launch before an in/out referendum in 2017 if he wins the general election.
His calculation goes that the German chancellor, Angela Merkel, is so determined to ensure that Britain remains a member of the EU she will help the prime minister agree on reforms of the EU to allow him to campaign for a yes vote.
Merkel's clear statements that Juncker must be nominated show that her patience with Cameron is finite, as it was over his tactics in opposing the fiscal compact in 2011.
More ominously for Cameron, as he looks forward to the 2017 referendum, the last few weeks show that Merkel has far less room for manoeuvre back home as she seeks to accommodate British concerns.
The German chancellor had initially shared Cameron's concerns about Juncker and had belatedly endorsed him as the spitzenkandidat – the lead candidate for the European parliament's centre right EPP group – at a congress in Dublin in March.
But she was forced to offer unqualified backing for Juncker after a domestic backlash when she suggested last month that other candidates should be considered.
Kerr warns that Cameron has unwisely "burnt" Merkel by campaigning so personally against Juncker rather than making arguments in private about the principles behind his thinking.
"We played the man not the ball which is fair enough provided you are not caught doing it. We did it too obviously," Kerr said. "It should have been ostensibly all about concepts – instead of which we burnt her off."
The prime minister is taking such a strong stance because he believes the European parliament is embarking on what he has described as a backroom power grab.
Cameron also believes that Juncker, a veteran Brussels fixer, symbolises the EU's past and will veto the reforms Cameron's party wants.
Some ministers fear the row may prompt Cameron to signal he is prepared to campaign for a no vote in the referendum if the appointment of Juncker is followed by a failure to embrace reform.
Michel Rocard, former French prime minister, concluded it would be better for everyone if the UK just packed up and left the EU. There are plenty of influential EU players who agree with Rocard, that it is time for the UK to put up or shut up. ut they are not in a majority. Elite opinion across northern Europe, in the newer states of eastern Europe, and in parts of the south, is keen to perpetuate the British contribution to the EU. The Irish, in particular, are extremely worried about the national impact on them of Brexit.
And the European commission, for the past 10 years under José Manuel Barroso, has arguably been more "British" in its agenda than it has ever been.
But in Brussels, the common view is that if you are looking for a fight, you have to pick them carefully; be sure the fight is worthwhile, build alliances, proceed gingerly, and be confident of winning.
It is here that Cameron is seen to have had clay feet. In the past five years he has picked three big fights and lost them all. In the process he has spent his political capital, provoked accusations of bullying and blackmail, made enemies, and marginalised the UK.
"It has been inept," said a senior EU official. "But Cameron seems to judge his performance purely by watching the opinion polls. A lot of this is about his management of the Conservative party. Any thought of the national interest? Nobody seems to talk about that."
His backbenchers may have cheered, but Cameron got off to a bad start in 2009 by pulling the Tories out of the mainstream centre-right grouping, the European People's party, led by Merkel's Christian Democrats and comprising a majority of EU government chiefs.
They view this grouping pragmatically, as a vehicle for cutting deals on Europe. Cameron forfeited that influence. That decision has had far-reaching consequences in the current showdown. It meant the conservatives were absent and had no say when the EPP met in Dublin in March for a congress that supported Juncker's commission candidacy. A cooperative Cameron arguing from inside the tent would have been likely to have got a better hearing.
Merkel was cross with Cameron back in 2009, but put the rift behind them. Again, the impact of that 2009 decision had to be repaid with interest a fortnight ago when the Tory-led group in the parliament admitted the anti-Merkel and anti-euro Alternative for Germany to their ranks.
Cameron did not want this to happen for fear of alienating Merkel. But he could not stop it, indicating he had lost control of the political movement he had created.
A considerably bigger mistake was made by Cameron at the height of the euro crisis at the end of 2011 when ge embarked on a doomed solo crusade to stymy Merkel's eurozone fiscal pact, her favoured instrument for institutionalising and entrenching austerity across the single-currency countries.
Cameron took the unprecedented step of wielding a British veto at a Brussels summit in December that year. He demanded concessions for the City of London and on financial regulation in return for his support. The others balked.
The veto prevented the fiscal pact becoming EU law. But Merkel and all others, except the Czechs, simply bypassed Cameron and concluded the pact as an international treaty between signatory states.
Cameron got none of his demands. He did not prevent the pact. His nuclear weapon was a dud. And under the treaty, the pact becomes EU law by 2018 at the latest in any case.
The ineffective use of the veto is particularly instructive in the current showdown, Cameron's third big lost battle. EU summits have only ever agreed to nominate a commission president by consensus; that this is way EU summits work, that there should be no vote. But if Juncker is proposed Cameron will insist on a vote.
The tacit rule is that EU summits operate by consensus. Votes are always avoided. But British invocation of that argument is undermined by the fact that it was Cameron who rolled out the veto in 2011.
He achieved nothing, at least in Europe – a scenario that is likely to repeat itself on Friday.
The picture over Juncker is more nuanced than the Rocard intervention might suggest. If the dust settles around a Juncker nomination on Friday afternoon in Brussels after an unprecedented vote is lost by Cameron, Merkel will not relish the victory.
Unlike Cameron, she will have snatched victory from the jaws of defeat, although like him she will have put her own personal and political party interests first in calculating whether to oppose Britain. She has invested heavily in the relationship with Cameron.
In every statement she has made on the Juncker question since the European elections, she has sought to balance her own interests in backing the Luxembourger with words aimed at soothing British pain and accommodating UK concerns.
She told the Bundestag she was shocked to hear how serious people in Germany could talk so nonchalantly about getting rid of Britain. Her view is echoed by Karel De Gucht, the European trade commissioner, who said that only "stupid" people believed the EU would be better off without Britain.
The commissioner told the Guardian: "There is an overwhelming majority of member states and European politicians that are of the view that the UK should stay in the EU. We would weaken the EU if the UK left. People who would be happy if the UK left are rather stupid.
"It is a big member state so it would create an atmosphere that might inspire others [to leave]. It is a big economy and has major links worldwide. The EU does not want to see people leaving, it wants to see people coming in."
The prime minister's expected defeat over Juncker is changing the dynamics among Eurosceptic Tories who are assessing tactics ahead of Cameron's planned referendum. The main Eurosceptic groups have agreed to be supportive of the prime minister in the runup to next year's general election because only Cameron will deliver a referendum.
The Juncker row is strengthening the hand of hardline Eurosceptics who believe the prime minister will struggle to achieve much of substance in his EU negotiations. One source said: "The only real significance of this that those of a eurosceptic disposition have been hardened in their position. It makes it more likely that people will have a higher threshold for what they would consider acceptable for a renegotiation and a higher expectation of what could be achieved."
There is a growing consensus among the Eurosceptics that Cameron should go further than he is planning by pressing for Britain to remain a member of the EU's single market while breaking links with all other aspects of the EU on foreign policy, justice and home affairs and possibly withdrawing from the European parliament.
In a sign of how the debate is moving on, some eurosceptics believe Britain may secure the best deal after a no vote when two years of exit negotiations would be held under the terms of the Lisbon treaty.
One source said: "The end game is going to be a much more complex set of treaties and far more variable geometry, some who are eurozone, some who are euro plus elements of political integration, some who are at present EFTA or EEA.
"If a British government pulled off a deal which said we are in the single market, albeit that means we have got some financial payments to make and we can be bound by the European court of justice on market decisions – that would command popular support in the UK."
The ambitions of the Eurosceptics, which go way beyond the plans floated by the prime minister, show the danger of tacking in their direction.
"Cameron has tried to keep the Eurosceptic dragon at bay by feeding it bits of red meat," Charles Grant, the director of the Centre for European Reform thinktank, said. "But it is a dragon that always comes back for more. It is not satiated."
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