[3] From 1909 he was married to Edith née Heiman (died in Jerusalem in 1949) and was the father of Yonatan (Theodore) Hantke.
[2] With the outbreak of the First World War, he transferred with Otto Warburg the Zionist Executive to Copenhagen, which was neutral, and at the same time worked with the aid of the Jews of Eastern Europe who were under German occupation and with the Germans trying to influence the Turks not to destroy the Jewish community in Eretz Israel.
[3] Following the deportation of the Jewish population of Tel-Aviv and Jaffa during World War I by the Ottoman commander Djemal Pasha, Zionist support for the Entente grew.
Hantke met with Ottokar Czernin, the foreign minister of Austria-Hungary, and received the following statement:[6][7][8] We appreciate the desire of the Jewish minority in countries where they have a strongly developed culture of their own, to pursue their own way of life and we are willing to give benevolent support to these aspirations ... With regard to the aspirations of Jewry, especially of the Zionists towards Palestine, we welcome the recent statement of Talaat Pasha, the Grand Vizier, as well as the intentions of the Ottoman Government, made in accordance with its traditional friendship towards the Jews in general, to promote a flourishing Jewish settlement in Palestine, in particular by means of unrestricted immigration and settlement within the absorptive capacity of the country; local self government in accordance with the country's laws, and the free development of their civilization.In 1919, he initiated the establishment of the Central Zionist Archives.
In 1926 he was appointed as a director of the Keren Hayesod and immigrated to Israel, where the Central Bureau of the Fund was located.