Masada, in brief, involved a sect of Jewish rebels who, after their fighting their way into Masada, ultimately and finally chose mass suicide, men, women and children, rather than face inevitable Roman conquest.
Jewish history is replete with attempts to destroy as many Jews as possible, culminating in Holocaust genocide, the meaning of which continues in the modern ongoing existential threat posed to Israel by her neighbouring enemies.
So Ari Shavit writes, "But the debate was neither moral nor ethical. In the Israeli siege-republic of the 1950s and 1960s, the memory of the Holocaust felt very close, as did the existential threat. Both of these factors underpinned the general agreed-upon moral justification regarding the right to acquire a nuclear option."