Complex sentence: The time came for JDC to shift its focus in Europe from emergency relief to long-term rehabilitation, and a large part of its evolving mission involved preparing the Jewish refugee population for new lives in Palestine, soon to be the Jewish state of Israel.
Split into simpler sentences: The time came for JDC to shift its focus in Europe from emergency relief to long-term rehabilitation. A large part of its evolving mission involved preparing the Jewish refugee population for new lives in Palestine, soon to be the Jewish state of Israel.