ROB, I would like to point out where you are wrong .
1)There was not a lot of Torah in Lithuania and Poland in the 20-th centuary. There were a couple of yeshivos — a miniscule percentage of the general Jewish population. The people were going or already were off the derech in masse.
2)If not for all the learning in golus, there would have been more pogroms. And in Spain s lot of Jews were busy learning philosophy and sciences instead of the Torah.Chazal said that the Torah protects and bittul Torah can bring on tzaros. We can not always know why things happen, but Chazal and later Gedolim would sometimes tie certain tzaros to certain aveiros.