Israel braces for influx of Jews fleeing Russia

It seems similar to what happened prior to WWII when the Ottoman Empire allowed huge numbers of Jewish refugees from Russia (the largest Jewish population being in Ukraine) to emigrate to Palestine. It started well before the 1900s actually - because of the pogroms being carried out by Russia. Anyone who has seen "Fiddler on the Roof" knows how the scenario plays out. I have never understand why Russia has targeted Jews for centuries.
Since the last wave of "the Mongol Hordes" ruled the area in medieval times (there were so many waves I don't know which one it was) the Ukraine has primarily been in the sphere of Russia's ruling influence, including becoming part of the Russian Empire. In other words Ukraine's few times of independence have been minimal compared to the amount of time it has been under Russian control. So it is no surprise Jewish folks are leaving Russia - to avoid the draft. Many probably have roots in the Ukraine, and family too, who do not want to be part of what is participating in attacks in Ukraine . . . and perhaps they fear reprisal from Russia (think camps for Japanese folks in U.S.A. during WWII) if they do have family in Ukraine.
I guess one question is whether or not the population of Ukraine is largely Jewish, still - which could seem like a Russian intention to target Jews - again or still. Another is when Israel announced it was taking in refugees from Ukraine, was it was limiting immigration to only being Jewish Ukrainians.

A call up is one thing, but a targeted call up aimed at ethnic minorities is quite another thing.