Although we do not know Hashem’s ways, you can ask your Rebbi or LOR if you want to get as close as possible.
Having said that, liPilpula biAlma:
I think Ben Levi’s post re: R’ Shmuel Berenbaum is instructive.
There are other factors as well, both spiritual and, lihavdil, material:
1. Rav Elchonon HY”D wrote, before the Holocaust, that Hashem created, midah kiNeged midah, a merger of the two idols served by Jews at the time: Nationalism (i.e. Zionism) and Socialism.
2. Kivan sheNitan rishus…
3. liHavdil, on a material level, there was the very existence of Zionism as well as Zionist treachery that were major factors as well. (This is not a secret, much as the Zionists wish otherwise and blaspheme and besmirch our gedolim in attempting to rewrite history. See R’ Weissmandl, R’ Avigdor Miller and many others, in addition to researched and documented secular sources.)