How long have Palestinian leaders been misusing aid money? Literally since “the beginning”—early Mandate era, as this passage from Porath’s “Emergence of Palestinian Arab National Movement vol.1” shows 
How long have Palestinian leaders dismissed opponents and critics, using patronage to consolidate their agenda and power? Literally since the beginning.
How long have Palestinian leaders been using education to teach the next generation rejectionism? Literally since the beginning. [SMC=Supreme Muslim Council, led by Amin al Husseini]
Prohibiting selling land to Jews? Also not new. Of course, that hasn’t stopped key Palestinian leaders, including the al-Husseini and Tamimi families from doing just that, as I’ve noted elsewhere.
