The Yishuv wanted to help their fellow Jews , who were being murdered by the Nazis in Europe . Many Jews from Europe were prevented from fleeing to Mandatory Palestine by strict immigration quotas established by the white papers . The Jewish Agency organized illegal immigration from 1939 through 1942 with the help of the Haganah . Those who arrived illegally to Israel during this time were part of the Aliyah Bet . This was a dangerous operation , for these illegal immigrants arrived by boat and had to be careful not to be caught by the British or Nazis . Many of these ships sank or were caught , such as the '' Patria '' , '' Struma '' and . Compared with the number of attempts , few ships actually arrived successfully to Mandatory Palestine , but tens of thousands of Jews were saved by the illegal immigration
Struma
Struma disaster
Yishuv