A group of Haganah members, who subscribe…

A group of Haganah members, who subscribe to the views of Revisionist Zionism, leaves the organization in protest against its "defensive" orientation and joins forces with Betar in April 1931 to set up a new and more militant armed underground organization, known as the Irgun.

The formal name of the Irgun is the Irgun Zvai Leumi (National Military Organization), sometimes also called by the acronym, Etzel, from the initial letters of the Hebrew name.

It is at first supported by many non-Socialist Zionist parties, in opposition to the Haganah.

Betar (which will later form a nucleus for Herut) and Irgun reject the Histadrut/Haganah doctrine of havlaga (self-restraint) and favor retaliation.

Irgun will not hesitate to use force against the Arabs.