Took part in anti-British operations, and in one of these, the attack on the southern railway lines (April 2, 1946) was seriously injured in the arm.
In 1947 was transferred to Jerusalem and participated in the War of Independence as a company commander. Among other positions, commanded the Irgun forces in the battle for Ramat Rachel and the assault on the Old City in Operation Kedem. Was twice mentioned in dispatches.
After the war, studied biochemistry at the Hebrew University of Jerusalem, and in 1960 was awarded a Ph.D. in biochemistry. In 1973 was appointed Full Professor at the Hebrew University.
In 1980 was summoned by Menahem Begin, then Prime Minister, to serve as his adviser, a task he fulfilled until 1985.
Published four books on the history of the Mandate period and the Revolt: