Our Facebook portraits are draped in the tricolore, special twibbons adorn our Twitter profiles, public buildings are splashed blue, white and red, we “pray for Paris,” we sing the Marseillaise, Nous sommes tous des parisiens: the aftermath of Friday evening’s pitiless slaughter of scores of mainly young friends enjoying themselves has seen an outpouring of expressions of solidarity with France, especially in Europe.

But this European solidarity seems pretty thin in real terms. This is not just because such expressions – ‘des badges, des tweets, des marches silencieuses, des vidéoclips ou des «chartes de la laïcité» (secular charters)’ – are inadequate to repel the nihilistic murder machine of so-called Islamic State (Da’ech) in the words of a savage leader by Figaro editor-in-chief Alexis Brézet urging war against this “army of crime.”

Europe is the opposite of united: it is falling apart. Even before the Friday the 13^th horror, the EU’s economy showed clear evidence of renewed stagnation and even a return to recession as world trade falters. The Eurozone limps along as home to a common currency, still likely to crumble. Britain, already halfway out, may lead a rush to the exit door.

The sheer scale of the refugee crisis has rent asunder core elements of integration: Schengen and the Dublin Agreement. The crisis is so acute one leading Brussels insider has given the EU just five months to save itself. Of the 160,000-strong redistribution quota agreed in the summer just 147 refugees have gone to other countries inside the Union.

And now Friday’s shootings and bombings will buttress the determination of member state governments to regain control of their national borders and keep refugees out. Already, Konrad Szymanski, the minister for European affairs in Poland’s new right-wing PiS government, has said Warsaw “must retain full control over its borders, asylum and immigration.” Such remarks simply deepen the east-west divide on refugees on top of the north-south chasm on the economy.

Even worse, the discovery of a (fake) Syrian passport used by one of the assailants as he passed in a huge crowd of refugees through Greece has brought the easily-stirred wrath of the Right down upon the heads of refugees – as if they were the real perpetrators of Friday’s atrocities. Ignoring the obvious point that, as Nick Cohen puts it, they flee to Europe, not from Europe, to seek succour and protection from brutal oppression – not to kill their new hosts indiscriminately. Unless civil society exerts enough contrary pressure to retain open borders, governments will impose Fortress Europe behind national drawbridges.

Worse still, the notion that Europe is in a “clash of civiliations” with Islam and at war, as a shaken President Hollande told the French public on TV late on Friday, simply plays into the hands of both Da’ech and the (Far) Right in Europe. Philippe de Villiers, head of the ultra-nationalist Movement for France, said the attacks owed their origins to “laxity and the ‘mosquéisation’ or landscaping with mosques of France” while the Front National’s Marine Le Pen (already riding high in opinion polls ahead of regional elections next month) called for “rearmament” of a “weak” France to “annihilate Islamic fundamentalism”. Even the liberal-left Nouvel Obs gives space to a retired senior general to lament France’s unpreparedness for this ‘new type of war’ and to claim it is fighting alone.

More pertinent seems the comment by Gilles Kepel, political scientist and Arabist, that the goal of Da’ech is to “sow civil war in France”. It’s unclear yet how many of the seven or eight assassins were “returnees” or radicalized young French Muslims who went to Raqqa via (probably) Turkey to join ISIS and were sent back to their homeland to ratchet up a ‘war of religion/culture’. It appears two of the assailants lived in Belgium or were Franco-Belgians. (Both countries “send” far more (twice as many) young Muslims to Syria than, say, the UK). It’s certainly the case that France is the Number 1 European target for these murderous militants, partly because of its military role in Africa against Islamist extremism and partly because of its historic attachment to liberal secularist values (the ISIS statement claiming responsibility talks of ‘targeting the capital of prostitution and obscenity’).

But there are particular reasons why France has (twice this year) been vulnerable to such attacks. One is an obvious and catastrophic failure of intelligence on the part of the under-funded, under-resourced DGSI (French version of MI5/BfV) and what people in the know call silo mentalities and turf wars among various agencies tasked with national security. This is exacerbated by lack of co-operation/intelligence-sharing at European level. Another, post-Charlie Hebdo, is the failure to live up to the promises of enhanced measures to integrate disaffected young Muslims educationally and economically: the jobless rate can be 50%-plus in a depressed economy). Proportionally, France has the largest number of Muslims – around 5m or 7.5% of the population – in Europe.

But it is Europe that is (outside the Middle East itself) bearing the biggest brunt of the US-led decision to invade Iraq in 2003 – the source of much of today’s continuing destructive instability on both sides of the Med. In the intervening period it is still dithering and divided about how it should respond to conflicts within and outside its borders. Friday the 13^th is a clear historic watershed: either Europe bows to the angry, intolerant clamour of the Right and makes itself an authoritarian, xenophobic fortress or it re-asserts republican values of openness, tolerance, equality – while protecting all its citizens. Angela Merkel, German chancellor and protagonist of the latter option, rightly so, may be weakened by the bloody events in Paris but her sense that only a united Europe (“we need more Europe, not less”) can solve these immense problems remains correct. It’s what most if not all of those predominantly young victims of the assaults on our shared values believed in.