[2] Kessler wrote in his unfinished autobiography that when he read the booklet "The Jewish State" by Theodor Herzl, he felt he had discovered the solution to the problems that had troubled him in his student days.

Kessler was "greeted with enthusiastic applause" after presenting practical ideas for the Congress's Finance Commission, and was elected a member of the Greater Actions Committee.

He suggested publishing an Arabic newspaper and argued that Herzl should petition the Turks to remove the obstacles preventing Jewish immigration to Palestine.

Kessler declared that "optimism, Jewish energy, endurance and intellect, combined with a steady immigration into the country, would lead to the factual recognition of the historical claims of the Jews to Palestine".

In October 1902, Herzl met with the British colonial secretary, Joseph Chamberlain, and England tentatively offered El Arish in the Sinai Peninsula for Jewish colonisation.

"[5] Herzl received a document about El Arish from the British foreign secretary, Henry Petty-Fitzmaurice, and noted in his diary that it suggested Marmorek, an architect; Kessler, an engineer; and Otto Warburg, an agricultural expert, for the expedition.

Other members of the expedition included Selig Soskin, an agricultural expert, and Hillel Yaffe, a physician to the Jewish colonies in Palestine.

Also on the team were Marmorek; Albert Goldsmid, a colonel who had taken over Baron Maurice de Hirsch’s Jewish colonies in Argentina in 1892–93; Emile Laurent, a professor at the Agricultural Institute at Gembloux; H. Stephens, an engineer, to investigate water problems; and a representative of the Egyptian government.

The Egyptian government, calculating that the plan would require five times the amount of water Stephens had estimated, turned down the proposal.

Kessler, in a supplementary report, stressed that colonisation could be carried out without Nile waters (by damming wadis, sinking wells, etc.

There was enthusiasm for the proposal at the Sixth Zionist Congress, which voted by a large margin to set up a commission to investigate the possibilities of the territory.

On 27 September 1903 he wrote to Herzl that he considered it almost "hopeless to attempt to establish a purely European colony in the heart of Africa".

For that reason, he argued that the project should be handed over to the Jewish Colonisation Association (founded by Maurice de Hirsch), whilst the Zionist Organisation should concentrate only on Palestine.

[6] He opened the EZF's conference on 1 June 1913 by welcoming the appointment of a new chief rabbi, Joseph Hertz, an old friend of Kessler's from South Africa.

[7] He was elected to the board of the Jewish Colonial Trust, which became Bank Leumi, as early as 1903, and remained a member of its directorate for almost 20 years.