By Tim Lister, CNN
The far right in Europe has enjoyed a renaissance over the past 30 years, driven by resentment of the growing powers of the European Union and by rejection of the "multiculturalism" that has accompanied rapid immigration from the developing world.
Political parties opposing immigration and integration have done well in elections in recent years - and beyond them, neo-fascist and "national socialist" groups have become well-established across the continent, including in Germany, Belgium, the Netherlands, Italy, Scandinavia, Hungary and the United Kingdom.
Most of those belonging to such groups would not contemplate the sort of carnage that occurred in Norway on Friday, but they would probably sympathize with what appears to have been the manifesto of the alleged assailant, Anders Behring Breivik.
Breivik claimed that "cultural Marxism" had morally degraded Europe, and purportedly wrote: "You cannot defeat Islamisation or halt/reverse the Islamic colonization of Western Europe without first removing the political doctrines manifested through multiculturalism/cultural Marxism." Elsewhere he said: "One of the most widespread manifestations of the craziness of our world is multiculturalism."
There are plenty of white supremacists who subscribe to such views on websites like stormfront.org, whose motto is "White Pride Worldwide." On the site's discussion forums, one thread entitled "Scandinavia Struggles Against Multiculturalism" warns that "a united Europe could become a strong wall against Islamic 'cultural' invasion, but instead Europe has become a gateway for Islam." The thread, which has been active for several years, contains reports of alleged rapes by immigrants, warns about the low birth rate of native-born Scandinavians and links to videos of far-right protests.
Another thread is titled: "Please Nordic people, keep white Scandinavia." And the day before Friday's attack, one forum participant wrote: "Norway must wake up and deport non-whites."
In his own writings, the alleged Norwegian bomber appears to have complained about the "Muslim ghettofication process'" in Oslo - a term also used by the far right in Denmark.
Without espousing such apocalyptic views, far-right political parties in Scandinavia have tapped into this anger - and reaped dividends at the ballot box. The far-right Danish People's Party (Dansk Folkerpartis) has 25 seats in parliament; the Sweden Democrats Party won 5.7% of the vote in the 2010 election. In Finland, the True Finns party made a dramatic breakthrough in April's elections, gaining more than 1 in 5 votes.
Beyond Scandinavia, France's National Front won 15% of votes in the first round of regional elections in March 2010, even though it was not on the ballot in the entire country. President Nicolas Sarkozy's party only managed 2% better.
In the Netherlands, Geert Wilders (a politician admired by Breivik in his writings) has successfully stirred up hatred against Islam and the establishment; his Party for Freedom has become the country's third largest, with 24 seats in the Dutch parliament. Wilders has compared the Quran to Hitler's Mein Kampf and has tried to have it banned in the Netherlands.