It is a democracy, the Parliament (Knesset) is elected every four years, they had periods of excessive stability (the Labor party reigned from 1948 to 1973, I believe). When no single party can put together a stable coalition (no party ever had a majority large enough to form a government by its own), a coalition of few parties is formed. From time to time, a coalition dissolves when government actions are in diametric opposition to one of the coalition's partner's philosophy. When that happens, the right thing to do in a democracy is to go to the people and let them decide through the elective process, which philosophy they support. Italy used to have government changes much more often...
Zeev