Europe has quite the history of bloodshed. They will recover in time to fight off the islam horde. It may be bloody but they will awaken.
I think there is no alternative to it being bloody since the enemy is Islam and Islamic radicals don't have a concept for peaceful settlement of problems with non-muslims.
European social and poltical attitudes can change in the twinkling of an eye. Look at the virtually overnight change from Weimar democracy to Nazi dictatorship. Look at the collapse of the Russian Monarchy or the later collapse of the Soviet Union.
The Germans were perhaps the most educated, civilized and technologically advanced people in the world in 1939. They ended up using all of the resources of their nation to build death camps and crush their neighbors.
Once the people of Europe decide to deal with the Islamic threat within their borders, I think even the most gung-ho of FReepers will be shocked at their ruthlessness.