 Complete the following phrase:  The return of several hard-line Palestinian Arab nationalists, under the emerging leadership of Haj Amin al-Husseini, from Damascus to Mandatory Palestine marked the beginning of Palestinian Arab nationalist struggle towards establishment of a national home for Arabs of Palestine. Amin al-Husseini, the architect of the Palestinian Arab national movement, immediately marked Jewish national movement and Jewish immigration to Palestine as the sole enemy to his cause, initiating large-scale riots against the Jews as early as 1920 in Jerusalem and in 1921 