This post is also available in:
English 
Español (Spanish) 
Italiano (Italian) 
Deutsch (German) 
فارسی (Persian)
Short answer
Radical Islam already brought horrific attacks in various locations in Europe. Continued growth of this mindset will lead to further mayhem and social instability in Europe.
Long answer
If radical Islam increases its influence in Europe, the possibility of increased jihadist atrocities is high. This extremism could transform societal norms quickly, fostering a community that supports, rather than condemns, jihadists. The fanatical belief of triumphing in the name of faith through force could spread, creating a significant, existential threat to the West. This is not a mere political issue; it is a long-lasting war that needs to be confronted decisively.
