"This issue is quite tricky - do you realize than no pogroms took place in Russia proper? They happened on the Ukraine"
This has virtually no basis in reality. Pogroms, state sponsored and otherwise, took place not just in the Ukraine but all over the Pale of Settlement (Lithuania, Latvia, Russia, Belarus, Ukraine, Poland) into which Jews had been herded by Russia, and particularly in Belarus, Russia, Latvia, and Lithuania. Herewith a map:
http://fcit.coedu.usf.edu/holocaust/gallery/pogroms.htm
"The reason was old conflict between Jews and Ukranians caused by the system of arenda of XVII century in which Polish nobles gave Jewish overseers absolute power over serfs in exchange for high fees. The worst largest pogroms occured during the peasant revolt of Khmelnitsky when countless Jews and Poles perished"
There were many reasons for the anti-Semitism which even today flourishes in Central and Eastern Europe. Jews were and are still hated for every reason under the sun: because they were rich, because they were poor, because they were weak, because they were powerful. The chief reason though was the virulent and incessant anti-Semitism spread by the Russian Orthodox and Roman Catholic churches.
The Khmelnitsky revolt had absolutely nothing to do with the pogroms which occurred in the territories controlled by the Russian Empire in the last thirty years of the 19th century and the first decade of the 20th century.
For those who doubt the very long history of Russian anti-Semitism, go to Google and search the terms "Russian anti-Semitism" and "Russia + anti-Semitism."
Furthermore, your own experiences of Russian Jews are obviously so limited that they can be utterly discounted. It is beyond dispute though that Israel, in an act of supreme insanity, let in hundreds of thousands of non-Jewish Russians who had zip feelings for the Jewish state in the last decade or so. It therefore wouldn't be surprising if they have run away at the first sign of trouble. In actual fact, very many immigrants to the US, especially from Eastern Europe (not Jewish) left these shores within a few years of arriving, so there is a precedent here.
To begin with, Jews not herded into Pale. Pale is where Jews living when Russia aquire such territories as in Ukraine and Poland. Thus they ordered to remain and not migrate further east, and again that apply to villagers not professionals. One such reason is the already land hunger in Russia proper.
My uncle is a jew from Ukraine, he move to Israel with family...he was engineer in SU...now (when little work is available) he works as factory worker. Since he does not speak English, he is not allowed technical work. They live poor now.
Oh and one last thing, we poor unwanted Christians, particulary Orthodox Christians live in Israel for 2 thousand years now. Israel is not a Jewish only state.
You got it upside down. Jews were not "hearded" into the Pale. The Pale which was acquired by Russia from Poland.
Russia like Scandinavian countries, United Kingdom and numerous other countries did not allow Jewish emmigration. Only in the XIX century Jews from conquered Polish territory were allowed to immigrate to Russia proper (which was much more attractive). But this immigration was limited until Bolshevik Revolution.
Ukraninian peasants and their descendants have long memory of their serfdom and until now there is a lot of resentment against "Polish pany and their overseers".