Hanoch Kalai made aliya in 1924, he joined the Haganah after the 1929 riots, and in 1933 he joined the Etzel. He was among the initiators of the havlagah breakers. He was intermittently in charge of Etzel branches in Kfar Saba and Herzliya and Commander of the Haifa and Jerusalem districts. In May 1939, with the arrest of Commander-in-Chief David Raziel, Kalai was appointed head of the HQ. He asked Yair to return from Poland to join in managing the underground in Israel. Together, they launched a series of attacks on British targets.

On the night between August 31 and September 1, 1939, Kalai was arrested together with Yair and members of the Etzel Command, and they were detained until June 1940. After their release, Kalai drafted Command notice 112, in which Yair and his friends reject Raziel’s British-supporting approach. Then, at Yair’s request, Kalai started working on the first drafts of the Lehi Principles. At the time of the split from Etzel and the foundation of Lehi as a new revolutionary underground, Kalai was Yair’s closest and most trusted associate.

However, during the year in which Yair, Kalai, and Binyamin Zironi served as command of the resistance, Kalai began to resist the continued attempt to contact England’s enemies, and he also opposed plans to confiscate funds from banks. Together with Zironi, Kalai negotiated a return to the Etzel. Their actions, undermining Yair’s leadership, caused him personal pain and caused damage to the resistance. Towards the end of 1941, the two men were rejected by the other commanders, and they withdrew from command and all Lehi activities. On February 3, 1942, Kalai’s and Zironi’s photos were published together with other Lehi leaders wanted by the British. They turned themselves in, were taken into custody in Israel, and then deported to Africa in 1944. Kalai returned to Israel in July 1948.