As for Stalin's initial support of Israel, well, he initially signed a secret non-aggression pact with Nazi Germany as well. One can read too much into foreign policy decisions.
Stalin, despite being non-Russian himself, targeted non-Russians in the Soviet Union in purges and deportations on the pretext that they were politically unreliable and potential spies. You can choose to take these excuses at face value, but in the end you have to recognize that in effect they suffered largely because of being the wrong ethnicity.
http://en.wikipedia.org/wiki/Stalin_and_antisemitism http://en.wikipedia.org/wiki/Antisemitism_in_the_Soviet_Unio...