One pic tell many stories: 1. Christians/Muslims united in Palestine 2. There was a flag pre 1948 Going back to pre ’48, there was nothing but deception and lies on the part of the future israelis.
However the League of Mandate included the Balfour declaration and gave the British the authority to run the Mandate.
The UN does not have authority under its Charter to create or divide states. The Partition Plan was a recommendation only.
The Plan envisaged a process, starting at the end of the Mandate, which would lead to the establishment of two states in a series of parallel stages. Because the Plan was rejected by the Arab side, it could not be implemented.
Borders can be changed, but a state can only acquire territory from a neighbor by legal annexation, that is, by agreement, and with a referendum of the population. Obtaining territory by war violates fundamental principles of the UN Charter. Nevertheless, this is what Israel did.