@DouglasCampbell 5 MKs from his coalition, Hamachane and the opposition could topple him. Each of the five parties in his coalition has at least five seats, so it just takes one party's defection.
Except by default that scenario would mean new elections. If he was willing to put his country and his party over himself (good luck with that), he could theoretically step down and let someone else take the role of PM. In 1974 Golda Meir resigned as PM in the wake of the Yom Kippur war, with Yitzhak Rabin taking over, which is the obvious analogy. Netanyahu could do the same, but knowing him, I really wouldn't bet on it. It seems to me that he's the type to go down fighting rather than exiting the political scene with grace.
@zzq Yes, somehow, I don't see him resigning, absent a major health issue. I'd give that a 2-3% chance. I also think there's a solid 1% chance he is assassinated. Other than that, the way he leaves is if one of his conservative coalition partners abandons him. While it could happen, this means an election.