One Monday in February, the Oslo media were ushered to the headquarters of an agency known as the Police Security Service for a surprising announcement. Intelligence agents had concluded that the most serious threat to Norway's security had become the combination of extreme right-wing international organizations and "Norwegian anti-Islamists."
"The combination of Russian neo-Nazis - with access to weapons - and Norwegian anti-Islamists is frightening," a police spokesman told the newspaper Verdens Gang. He described the combination of old-style extremists with "Christian people who will fight the Islamization," as they saw it, "of Norwegian society" as "a deadly cocktail that can explode at any moment."
But the announcement attracted little notice. "Some journalists laughed on their way to the press briefing, complaining that irregularities on the subway system were the greatest threat," one Oslo blogger said afterward.
Across Scandinavia, such warnings had been issued with increasing frequency in recent years. The sort of racially intolerant, violently charged language that had been taboo in politics since the Second World War had been creeping gradually into the edge of the mainstream in the years after Sept. 11, 2001. Some people further on the fringes were beginning to take that language rather too literally, the police warned.
Nobody quite believed them, though. Yes, Norway is a place where debates over immigration had long been heated, frank and very public, with the ruling social-democratic Labour Party and the right-wing opposition Progress Party at distant poles from one another.
But immigration wasn't a big deal even for most conservatives: Occasionally it rose in polls to become one of the top five issues on voters' minds, but it never quite reached the top three.
Norway, after all, has some of the toughest and most restrictive immigration policies in Europe. Its refugee process is unusually strict too.
As a result, even after 40 years of immigration driven by a booming oil economy's labour shortages, barely more than 10 per cent of its population are immigrants or their descendents - and the majority of those are Swedes, people from Baltic countries, Poles or other Nordics, most of them indistinguishable from the native population. Members of visible minorities are few, mostly clustered in the capital.
Even Norway's Muslims, mostly Pakistani or Somali and considered well-integrated by European standards, did not consider these rising voices of intolerance a major threat. Not until last Friday, at least.
"We knew that there were anti-Muslim movements, but not to this degree. We always thought that they would keep to their argument that there were too many Muslims," says Kadra Yusuf, a Norwegian of Somali descent whose activism had been directed against religious conservatives in the mosques of Oslo, notably in the fight against female genital mutilation.
Debates about immigration never struck Ms. Yusuf, 30, as something that could produce terrorism. "We have a tradition that we argue and fight in newspapers and politics, but everyone gets to have something to say - it never occurred to us that these people would feel the need to turn to violence. It has always felt very safe here. Our biggest fear was that someone from within our own community would do something extreme."
But something was quietly happening on the edges of the debate. The old arguments about whether immigration levels should be high or low, or whether cultural integration should be a matter of explicit policy or not, had shifted into a harder language, one that spoke of enemy races and religions seeking to take over the continent and enslave Europeans.
For the few who listened closely, it sounded strikingly similar to the language of Norway's old neo-Nazi parties, which, after several decades of visible activity after the war, had been outlawed and driven underground in the 1990s. Their rhetoric was back - including their furious hatred of social-democratic parties that dared "appease" the enemy race - but this time directed at a different minority.
"After 9/11, the way people talk about Islam and Muslims here has slowly, inch by inch over the years, moved," says Hege Ulstein, the chief political writer of the Oslo newspaper Dagsavisen, "so that things that would have caused total outrage and made people's heads blow up 10 years ago only cause mild annoyance today - things like 'there is something in the Muslim culture that threatens us and we have to send them away.'
"You couldn't say that then, and you hear it in Parliament and in the newspapers now."
This erosion was happening across northern Europe.
In neighbouring Denmark, the far-right Danish People's Party - whose platform often sounds like parts of the 1,500-page anti-immigrant manifesto written by Anders Breivik to justify his crimes - is now the third-largest party in Parliament, with 14 per cent of the vote. In Finland, the even more harshly xenophobic True Finns have a fifth of the vote.
And in Sweden, the far-right Sweden Democrats, whose platform is almost entirely anti-Muslim, won their first parliamentary seats, 20 out of 349, in last September's election.
Here in Norway, the right-wing Progress Party - which had purged most of its radical anti-immigrant branch in its quest for mainstream power in the early 2000s, and is generally a centre-right party today - had begun to allow extreme and sometimes violent-sounding messages to emanate from its rightward flank.
Last year, Christian Tybring-Gjedde, the party's finance critic and head of its Oslo branch, wrote a furious attack on immigration in which he described Muslim immigrants as having "the goal of stabbing our culture in the back" and warned that their presence "will tear our country apart."
"You will find some people on the outskirts of that party who could have written the same sorts of things that Breivik wrote before he committed his crimes on Friday," Ms. Ulstein says, "and that is very disturbing to think about."
Disturbing for some. For others, the explosion of violence unleashed by Mr. Breivik seemed to open doors for bringing such angry political rhetoric even further into the mainstream.
In the seven days since the atrocities of July 22, the most visible response in Norway has been the hundreds of thousands of people who have come into the streets of Oslo to deliver a message of tolerance and moderation. Prime Minister Jens Stoltenberg seemed to epitomize this message with his call to respond to the killings with even more democracy and openness.
But elsewhere in the city, far away from the crowded streets, the crimes produced a rather different response.
"I think it will become a more open debate after this incident," says Arne Tumyr, a right-wing activist whose website SIAN (Stop Islam in Norway) was frequented by Mr. Breivik.
"Of course we have nothing to do with his violence - we have sent him into the dark. But this new debate is a great opportunity for us to educate Norwegians about the truth, which is that Muslims are not a religion, they are a political fifth column out to take over our part of the world."
It is impossible to know whether this new sort of terrorism will bring about a mass public revulsion at such messages, or if it will provide a new and high-profile platform for people like Mr. Tumyr.
"These days," says Anne Holt, a Norwegian crime writer and former justice minister, "people talk beautifully about closeness, cohesion, care and love. The truth is that there are thousands and thousands in Norway who feel disconnected from all of this. The truth about Norway is that more and more people are left out."
Until last Friday, hardly anyone noticed.
Doug Saunders is a member of The Globe and Mail's European bureau.