Qasim's support as prime minister steadily narrowed. By 1960 he had suspended organized political activity and repressed both right- and left-wing civilian and military elements when it seemed that they might compete with his authority. His rule was supported only by the army, but in the spring of 1961 a rebellion broke out among the Kurds--an ethnic group acutely conscious of its cultural differences from the Arabs and to which Qasim had neglected to fulfill a promise for a measure of autonomy within the Iraqi state. This Kurdish revolt undermined even Qasim's military support, as much of the army became tied down in a seemingly endless and fruitless attempt to put down the rebellion. This situation, along with the discontent produced by repeated military purges, drew a number of officers into open resistance to the Qasim regime. 'Abd as-Salam 'Arif led dissident army elements in a coup in February 1963, which overthrew the government and killed Qasim himself.