Yes, it's safe. Terror attacks get a lot of publicity but they're still quite rare and limited in scope. And for the record, Muslims are not the problem. Prior to 9/11 the deadliest terror attack on US soil (Oklahoma City bombing) was committed by a group of white Christian Army veterans. A staggering number of shootings, bombings, and arsons have been committed by Christians against abortion clinics and LGBT activist organizations, but those never get news coverage. Dangerous ideologies can come from anywhere, and you're better served looking at the environmental and psychological aspects of radicalization than you are obsessing over what religion someone belongs to.
That being said I lived in Europe for a while after 9/11 and I've traveled all over the western half of the continent, from Ireland to Slovakia. Overall, it's a very safe place to be.