A wave of nationalism broke out in Europe in the years prior to WWI. (The end result was that after the war some countries, i.e. Hungary, Austria, were broken up into nation-states, i.e. Czechoslovakia, etc.
It was in this pre-war period that the Jewish Nationalists, i.e. Zionists, hopped unto that nationalism bandwagon breaking out to seek and later demand their own nationalism.
When Uganda didn’t work out they moved on to Palestine.