The British were fighting the Nazis and some Arab groups sided with the axis (mostly against the British colonialism). The naza tried hard to get to what is now Isreal and had special death squads set up to go in. The war solidified the need for a Jewish state, and it wasn't just a random decision, nor was the animosity between the Jews and Arabs new - many Jews saw the Arabs as extensions of the Nazis that had tried to exterminate their race. So what was Britain to do? Let the Nazis win? They created Isreal as per the new world government. It was a shitshow, but it was a shitshow well before Isreal was created.
This is not a commentary related to the current genocide that Isreal is doing. I think Isreal has lost its right to be a country as it is now. But who's going to impose a new 'solution' - you know in 50 years people will be saying this new solution, whatever it might be, is morally reprehensible.