In New York, exiled Jabotinsky, leader of Hagaah Bet, also disapproved of attacks on civilians but nevertheless, stayed on as overall commander of Irgun until his fatal heart attack in 1940. Inside Palestine David Raziel was now commander of Irgun, ably assisted by an explosives expert and supported by his mentor, the Irgun commander in Europe, Avraham Stern.

Stern was responsible for smuggling Jews illegally into Palestine and training Jabotinsky's Beter army of 40 000 to invade Palestine and wrest it from the British. David Raziel and Avraham Stern collaborated to write a text book on firearm usage and composed the Irgun's aims and principles. In addition Avraham Stern, a brilliant scholar and master of spin, concocted Irgun's propaganda.

Their explosives expert devised bombs with far more killing power than anything the Arabs had managed to create. The local Irgun, many trained in Poland as members of Betar, detonated them in crowded Arab markets. They also left time bombs on trains and a first ever letter bomb in the main Jerusalem Post office.

The situation could no longer be controlled by a civilian police force.