Idk, I think decades of serious suffering, oppression, and the looming threat of the annihilation of your people seems like just about as much justification as one could have. I feel like, to say otherwise is to tell the palestinians to shut up and take their genocide with a smile. Peace negotiations have and will get them nowhere, violence, as extreme as they can muster, is the only option they have left. Yet, it pales in comparison to what can be done back to them, and without intervention the state of palestine and its people will cease to be.