I’m not Israeli but I’m a life-long friend of Israel.
While the USA is a better ally, it doesn’t hurt Israel to maintain cordial relations with Russia. Many Israelis came from Russia (specifically, the USSR) and have maintained ties with Russia. For example, former Defense Minister Avi Lieberman was born in Kishinev, and speaks fluent Russian.
Jewish history should teach the importance of never placing your trust in one person, people or nation. Jews have been betrayed countless times in places where they were formerly welcome going back 2,500 years.
Russia and China should be Israel’s Plan B if America turns its back on the nation. Given the rising anti-Semitism in the USA and Europe, especially on the Left it’s a good strategy.
No friends of Israel (source)
If the US shifts leftward as expected in the fall 2020 election, those connections to Russia and China will be critical to keeping the country secure.