Justin Trudeau’s Canada offers a liberal, progressive face to the world, one that surely should be applauded in an era of rising bigotry and populism. If Donald Trump is elected, European democrats may increasingly turn to Canada as an important interlocutor across the Atlantic. So how is it that the European Union’s trade dealings with Canada ended up becoming such a focus of anger? Surely Canada, with its solid democracy, its tolerance and openness, stands out as a haven of decency. As Canadian trade minister Chrystia Freeland said, Canada is a “country that shares European values”.

But friendliness to Canada has not been readily on offer among parts of Europe’s radical left. Instead, the Canada-EU Comprehensive Economic and Trade Agreement (Ceta) – a 1,500-page document seven years in the making – became the target of a spectacularly hostile campaign. For those who waged it, this was a battle in which democracy itself was at stake, not just the question of whether Europe would suddenly be swamped with chlorinated chicken or hormonally altered beef (which it won’t). That Justin Trudeau called the text “progressive” mattered little.

Across social media, warnings were rife that the deal was a “Trojan horse”. Belgium’s Wallonia region (3.5 million inhabitants), which set out to oppose Ceta, was heralded as a champion defending the rights of all European citizens (508 million people). In the end, the treaty was signed, after an “interpretative” document was added to it – but without a single word of the treaty itself being changed.

Jean-Claude Juncker, the president of the EU commission, stated an uncomfortable fact. “Nobody protests when we sign an agreement with Vietnam, which is a great democracy. But there are protests when we sign with the terrible Canadian dictatorship,” he said. That did little to sway Ceta critics. These days, anything that smacks of officialdom or of “the establishment” gets swiftly disqualified.

I’m not saying Ceta is perfect, nor that it shouldn’t be scrutinised. Of course, in the negotiation of free trade deals, interests can collide. Finding the right compromise is essential. The anti-Ceta movement in Wallonia and elsewhere was worried about a system of arbitration courts not being independent enough from the pressures of big business. What the objectors overlooked was that Ceta introduced more government oversight than any prior EU trade agreement.

Ceta has been maligned as a dangerous step towards TTIP, even after that deal was put on hold

Rather, I’m asking why so much wrath came down on an EU agreement with a country whose friendliness and proximity to European social-democratic principles should have inspired more trust. Ceta has been maligned as a dangerous step towards the EU-US TTIP agreement, even after that deal was put on hold, if not buried. Ceta also suffered from the Brexit vote, which made governments in Paris and Berlin worry about demands to “repatriate” powers from Brussels. As a result, Wallonia, where the ruling socialists were under pressure from the anti-globalisation radical left, got its 15 minutes of fame. It temporarily blocked the deal with Canada, making the EU look dysfunctional.

These days, the question of what triggers outrage and what doesn’t could be a good topic for academic research. There are so many daunting international issues, from mass slaughter in Syria to refugees drowning off European shores, yet these tragedies fail to produce the same kind of grassroots mobilisation that free trade agreements do.

This is not to say that holding multinationals to account isn’t important – it is. But when looking at the crowds that gather in European cities on trade issues (300,000 demonstrated in Berlin a year ago against TTIP, and other, if smaller, public protests were held against Ceta), I’m reminded of another episode of selective indignation.

Canada’s prime minister Justin Trudeau. Photograph: Chris Wattie/Reuters

This was during the 2009 Copenhagen summit on climate. Tens of thousands of activists demonstrated to exert pressure on negotiators, and rightly so. But one of their key slogans was in support of the G77 group of developing nations, which that year happened to be chaired by Sudan – a country whose government had been carrying out atrocities in Darfur, and whose president had just become the object of an international arrest warrant issued by the international criminal court. None of this awkwardness got much mention at the time from climate protesters.

That said, the anti-Ceta movement has served a purpose. It has forced EU officialdom to think much harder about how it needs to convince citizens of the benefits of free trade, at a time when trade has almost become a byword for evil. It has also helped ingrain the notion that transparency and pedagogy (the task of explaining, tirelessly) are essential to the very survival of the European project. At least citizens have stopped ignoring what Brussels is up to.

Trade is a key area where the EU must act as a bloc if it is to be effective globally (if it doesn’t, then China will set the rules). But now, Ceta will likely be held hostage to 38 national and regional assemblies across Europe. This kind of local “vetocracy” is also what happened to the EU-Ukraine association agreement, blocked by a Dutch referendum that required just 300,000 signatures to go ahead. Those who think such trends are good for the anti-globalisation struggle should reflect on how they also affect efforts to forge a decent EU policy on refugees – basically, shattering them.

What’s perhaps most disturbing is that Ceta has been as much criticised by Europe’s far left as it has by the far right. This uneasy but real convergence of some progressives with constituencies that applaud Donald Trump and other nationalist populists should be scrutinised. No doubt it will have been noticed in friendly, democratic Canada.

• This article was amended on 7 November 2016. In the penultimate paragraph it originally said that the EU-Ukraine association agreement was blocked by a Dutch referendum in which 300,000 people took part, but in fact more than 4 million took part. The referendum required 300,000 signatures before it could be conducted.