The Arabs felt betrayed when the British occupied Palestine after WWI because they had been promised independence.
During WWI:
When the war was over and the Arabs had fulfilled their side of the bargain, the British and French instead occupied Arab lands such as Palestine. This led to the Arabs being betrayed as they simply got new masters instead of independence.
In conclusion, the Arabs felt betrayed because the British had renegaded on a promise.
Find out more on this betrayal at https://brainly.com/question/9229519.