The title of an article in New York Magazine asks the question, "Whatever Happened to the Israeli Left?" Israeli politics isn't really my issue, or my concern. Thinking I (and you) already know the answer, I skipped it. See if you agree with my answer to that question.
Faced with an implacable enemy in the Palestinians, who are supported be the Iranians, they did what they needed to do to survive ... they got really tough. That meant putting an emphasis on performance and accomplishment, ofttimes at the expense of social justice. They built walls, armed settlements, and became some of the best retail performers in the intelligence/counterintelligence field.
Along the way the kibbutzniks and Golda Meir socialists became Jewish neocons, "leftists mugged by reality" in Irving Kristol's felicitous phrase. Hard reality changes people.