The rise of the far right is the greatest threat to Western Civilisation

While there are always political extremists and malcontents in any society, the far Right(or the far Left for that matter) needs fertile ground to grow in. They don't spring from the ether. As topper75 notes Nazi Germany didn't come from nowhere. It can be directly linked with how Germany fared and was treated after The Great War in things like the terms of the Treaty of Versailles. It fostered economic hardship, social problems and a feeling of being made to take the entire blame for WW1. That's a vacuum something will rush to fill, and a few somethings did, from far left to far right, the "winner" was the far right.

Today the Right is rising in Europe in some quarters because of economic downturns, social problems, immigration and the feeling that enough seem to have of disillusionment with centre/mainstream politicians both locally and in the wider EU. The latter very much in play in Greece, Italy, Greece and the UK, hence one of the reasons for Brexit. If you're one of the large percentage of unemployed in say Greece and on the one hand you hear the EU calling for belt tightening, yet on the other hand you're also being asked to take in many thousands of migrants, many of whom are economic migrants, it's easy to hear the siren call of those who promise a fix and a feeling of national pride.

Here in Ireland I have far fewer concerns about any extreme politics coming in, right or left. Culturally and thankfully we tend to be more a "meh, sure it'll be grand" and leave our "extremism" in more local politics, and even there it's hardly extreme at all. Plus while we've had economic problems, we seem to be weathering them well enough and our geography also tends to keep immigration at a low level compared to the rest of Europe. Our lack of a direct colonial past helps here too.