Marxist: The Brits couldn’t care too bits about the welfare of “Palestine”. The need it to secure control of the seaway to the Raj, which was the “jewel in the crown”. The Brits knew who assassinated De Haan, and never objected. They knew about the 1929 pogroms before they happened, and made a point of encouraging it. Their greatest fear in the 1920s, when the “dice was cast” was that the agreement, acceptable to the Arab’s leaders, the zionists and the hareidim, and previously agreed to by the British, would go into effect, and there would be large powerful and independent Arab state east of Suez. The British Colonial Office played the zionists and the Arab for fools, and were successful at it. What we saw as a pogrom or riots, and the Arabs saw as an uprising, the British saw as an opportunity to maintain their Empire by making sure that the potential trouble-makers were too busy fighting each other rather than fighting the British.
The “divide and rule” policy was successfully implemented throughout the Empire, including Ireland and India. It was successful in starting conflicts which continue to this very day, but was a total failure at saving the Empire, which dissolved in a matter of months in 1947.