Rudolf Goldschmid Sonneborn (June 22, 1898 – June 1, 1986) was an American oil executive,^[1] businessman, and onetime president of The State of Israel Bond Drive.^[2]

In 1919 (aged 20) Rudolf visited Palestine from January to August, acting as the 'Secretary to the Zionist Commission'. He was investigating the feasibility of creating an independent Jewish State of Israel on its territory, achieved 29 years later on May 14, 1948. A detailed account of his trip was recorded in 'Letters Home'.^[3]

Rudolf Sonneborn and the secret of Makhon Z’

On July 1, 1945,^[4] David Ben-Gurion asked a small gathering of American-Jewish activists at Sonneborn's apartment to send supplies to the Jewish community and its military force, the Haganah.

Makhon Z’ – The Secret Project for Acquiring Arms for the Yishuv

The Makhon Z’ (Z’ Institute) was a covert operation conceived by Reuven Zaslani (later Reuven Shiloah) in 1945, aimed at establishing a network for acquiring military equipment and weaponry for the Yishuv in preparation for the anticipated conflict following the end of the British Mandate in Palestine. The project received full backing from David Ben-Gurion, who viewed it as a crucial element in preparing the defense forces for the upcoming War of Independence.

Background and Establishment

As mentioned before, towards the end of World War II, the leadership of the Jewish Yishuv realized that the British would continue to enforce the restrictive White Paper policies, preventing unrestricted Jewish immigration and limiting the development of Jewish defense forces. Zaslani, a close advisor to Ben-Gurion, argued that the Yishuv needed to prepare for a dual confrontation: first against the British and then against the Arab states following their withdrawal. Ben-Gurion accepted his assessment and tasked him with determining the essential resources required for the coming war.

The Secret Meeting in New York and the Formation of the Network

Zaslani orchestrated a clandestine meeting at the New York residence of Rudolf Sonneborn, attended by Ben-Gurion, Eliezer Kaplan, and seventeen prominent leaders of the American Jewish community. In this meeting, Ben-Gurion laid out his vision for the establishment of a Jewish state, Zaslani detailed the military necessities for achieving this goal, and Kaplan discussed the financial resources required.

At the end of the discussion, the participants resolved to establish the "Sonneborn Institute", which operated covertly within the United States. This network mobilized millions of dollars to purchase arms, ammunition, machinery for weapons production, and other military supplies to ensure the Yishuv’s readiness for the imminent armed struggle.

Makhon Z’ Operations and Its Impact on the War

For nearly two years, the network functioned in secrecy, circumventing legal restrictions that prohibited the transfer of military equipment to non-governmental entities. Following the withdrawal of British forces, Makhon Z’ went into full operation, and the weapons and equipment procured through this initiative played a crucial role in strengthening the Jewish military forces. The supplies obtained through the institute enabled the rapid organization of an effective fighting force, significantly influencing the outcome of the battles in 1948 and securing the Yishuv’s military advantage in the War of Independence.

The group became a secretive, nationwide organization led by Sonnenborn, Materials for Israel, also known as the Sonneborn Institute.^[5][6][7] Sonneborn was the fourth husband of New York Post owner and publisher Dorothy Schiff, a granddaughter of the American financier Jacob Schiff.^[5]