The Soviet Union recognized Israel because back in 1948, just about all of the Arab states were conservative monarchies, and Stalin did not expect to get very far when dealing with them. Egypt had King Farouk, Saudi Arabia had Ibn Saud, Iraq had Faisal II, Yemen had the Iman Yahya, etc. By contrast, many Jews at the time had socialist or communist leanings; Leon Trotsky is the most famous example. And the left-wing Labor Party dominated Israel for 29 years (1948-77), so the USSR had hopes that Israel would eventually join the Soviet Bloc. Thankfully it didn’t work out that way. While the Labor Party was in charge, here in America, supporting Israel was the liberal thing to do; now it’s the conservative thing to do.