The Russian "Mafia" is big in Israel, and is well established in NYC. Bear in mind, though, that many (if not most) members of the Russian "Mafia" aren't Jewish. After passage of the Jackson/Vanik Act in 1974 (which forced the former USSR to liberalize Jewish emigration from the Soviet Union), forged passports with phony Jewish surnames became very hot property in the USSR, so that people could escape to Israel or the US.
PP: Jewish gangsters were far bigger than the Mafia during Prohibition--they ran the booze trade in almost all major US cities except Chicago, and even there, a Jewish guy (Jack Guzik) was second-in-command to Capone. But they didn't "form" the Mafia. The Mafia was mostly (relatively) small, neighborhood mobs until after the Castellemmarese War of 1930-31. First, Salvatore Maranzano, the victor, formed the NYC mobs into five families. Then Charlie Luciano whacked Maranzano, formed The Commission and began building a modicum of cooperation among Mafia families around the country.