Many analysts (myself included) have quickly focused in on the impact of the far right in Europe in the context of the attacks in Norway. For example, Joerg Forbrig discusses the spread and success of the far right in an article on CNN's Global Public Square.
It must be kept in mind that the far right has not only found success at the regional and national level, but also in the European parliament. Another important point is that the far right, particularly organizations like Geert Wilder's Freedom Party and the English Defence League (as well as Defence Leagues which have formed in other European countries) have made linkages with anti-Islam and far right organizations in the U.S. This is not just a European problem it is a Transatlantic problem. Many far right organizations in Europe get funding and other resources from U.S. sources as well as wealthy supporters in their own countries (as detailed in investigations by the Guardian ).
Mainstream politicians in Europe have fed into the support for the far right by pulling far right discourses into mainstream rhetoric. Since I began studying these issues in the 1990s the rhetoric has clearly shifted towards the far right. Proclamations that "multiculturalism has failed" (particularly ironic in countries like Germany that have not practiced it) have fed into an emphasis on Muslims and their lack of integration. The securitization rhetoric has fed into the perception of Muslims as threat. Certainly this has not necessarily led to what happened in Norway, Breivik has been planning for many years and was motivated by his own demons. However, it is critical that mainstream politicians don't turn a small minority into a scapegoat for larger public ills.