The Ottoman regime, since late 19th century, imposed many harsh demands on the Yishuv, and was ended in 1918 when Britain occupied the territory, followed by the establishment of the British Mandate in 1922.
On top of these problems, the regime piled up additional difficulties such as war taxes and the confiscation of work animals, tools and food.
Other difficulties (either unrelated or not in direct relation to the regime) arose in the form of a locust attack (which the settlers were not equipped to deal with), famine and poverty (the result of donations ceasing), epidemics such as typhus, bank closures and inflation.
The attitude of the Ottoman administration toward the Jews hardened as their situation in the war deteriorated and it made the functioning of the Yishuv much harder.
First the Ottoman authorities canceled the regime of capitulation (immunity to foreign citizens) and as a result those that arrived from Allied countries (including the majority of the immigrants who originated from Russia) were now considered enemies.
In 1915 the Ottomans collected people walking the streets of Tel Aviv and Jaffa and deported them by ship to Egypt.
In 1917 the Ottoman deported the Jewish population of Tel Aviv and Jaffa as a result of the progress of the British front in the south of the country.
First, they needed an agreement from the president of the United States in sending the aid—this was the first time in which the American government operated a pro-Zionist policy.
The majority of the Zionist leaders supported and identified with Germany—it would be able to release Russian Jews from the burden of the czar, and Turkey which was a partner of Germany during the war would hopefully change its mind about the Jewish population in Israel.
In contrast with that, supporting the Allies of World War I might give a reason for the Ottomans to eliminate the Jewish settlement in the Land of Israel.