The monarchy and the constitution, with minor modifications, were key elements of the Iraqi regime until the revolution of 1958, when both were abolished as instruments of British imperialism. The Iraqi political system involved an interdependent relationship between two greatly unequal centers of power: Britain, which militarily controlled Iraq and its increasingly important oil resources, and the Iraqi monarchy, under great pressure to accommodate British interests. The treaty allowed Britain to hold on to its military bases in Iraq and use Iraqi government property until 1957, when the treaty would expire. King Ghazi attempted to arouse Iraq's people by assailing British imperialism and speaking against the creation of a Jewish homeland in Palestine through his broadcasts beginning in 1937 from a palace radio station. The Baghdad Pact allowed Iraq to run the British air bases at Habbaniyya and Shu'aiba while Britain retained the right to fly through Iraqi air space and use the air bases for refueling.