Lots to unpack here.
Massacres on a grand scale are taking place in the world today yet you feel safe to sit here and say that Jews face no real danger?
Massacres against Jews, on an grand scale? Where is that taking place in the world today?
And no, of course I wouldn't say that Jews "face no real danger." Anti-Semitism and anti-Semitic violence are vary much real. But the likes of the Hyper Cacher shooting, however horrific, do not provide nearly sufficient justification for a Holocaust II narrative. That act, and most present-day incidents of anti-Semitic violence in Europe referenced in the OP, are perpetrated by Muslim minorities - groups which are heavily marginalized in nearly every respect in European society - and are roundly and rightly condemned by the government of every state in which they occur.
Obviously,
this does not in any way justify these acts or make them less terrible, but it
does make them significantly different from the long history of atrocities against European Jewry up to and including the Holocaust, which tended to be committed by members of the ethnic/religious majority, with tacit or explicit backing from the state.
I do not dispute that anti-Semitism is a greater problem in Europe than in the US, or that anti-Semitic violence might be on the rise there. But it simply does not logically follow that the necessary cultural and political climate for large-scale persecution and violence directed at Jews in these countries exists, or is in danger of coming into existence.
You're saying this while a leading candidate running for presdient of the United States in 2016 just called for a ban of a certain religion from the country, but you come here and pretend that Jews are somehow immune to that?
Are willing to sit here and say that in X number of years from now Jews will not be the used a scapegoat again? What do you think it would take for the masses to turn their hatred towards Jews again?
By every measure I can think of, Jews are far better integrated into the mainstream of Western society, and have far more cultural, political, and economic influence (especially in the US), than at any prior point in the history of Diaspora Jewry. I would say Jews are about as well-integrated here in the States as Irish Catholics - a group which themselves faced significant discrimination in the not-too-distant past, yet one which no one argues is in any credible danger of becoming a persecuted minority again.
So yes, I really do feel quite comfortable in saying that large-scale persecution of Jews in the US or Western Europe cannot and will not happen anytime in the foreseeable future. I think it would take some completely absurd scenario, like Israel declaring war on the US, for that to change, and possibly not even that.
Who do you think the right-wing parties in Europe would focus right now if it wasn't for the Muslim immigration in recent history?
Another minority much less well integrated than Jews, I'd imagine.
But in any case, Muslim immigration to Europe is very much real, and if you're trying to argue that fear of a second Holocaust is completely rational, you shouldn't have to rely on impossible what-if scenarios.
You're living in some fantasy world where everything is fine and dandy. There are still millions upon millions of people who hate us. If you don't recognize that and the dangers it possess, you are blind.
Of course there are millions of people who hate Jews. But hate alone can't bring about another Holocaust; that requires both intent and capability.
If you want to argue that there is a group or nation out there that possesses both the intent and capability to murder millions of Jews, or is in danger of acquiring the capability, by all means, you're welcome to make that argument (as Bibi and his allies tried and - happily - failed to do in the debate over the Iran deal). But make it on the basis of facts.
---
Anyway: By all means, Jews absolutely should be vigilant about anti-Semitism. And I wouldn't even have a problem with the fear of a second Holocaust, irrational as I find it, if it were purely in the context of vigilance against anti-Semitism or bigotry in general.
But of course, it's not purely in that context at all. To the contrary, that fear is a huge part of one of the most common pro-Israel narratives: that Jews are a perpetually despised minority perpetually on the brink of extinction, and that Israel is all that stands between them and a hypothetical second Holocaust.
And sadly, that fear-driven narrative has very non-hypothetical consequences: actual warmongering against Iran; rationalization of actual atrocities committed by Israel like Protective Edge; justification for the continuation of the occupation and the oppression of the Palestinians. So if I seem contemptuous of it, that's why.