Richard Mulcahy, the new Irish defence minister, proposed to reduce the army from 55,000 to 18,000 men in the immediate post- Civil-War period. Tobin knew his own position was to be affected and shared the perception that the Irish Army treated former British officers better than former IRA officers. On 7 March 1924 Tobin, together with Colonel Charles Dalton, sent an ultimatum to President W. T. Cosgrave demanding an end to the army demobilisation. The immediate response was an order for the arrest of the two men on a charge of mutiny. The cabinet, already wary of the Irish Army, ordered an inquiry and appointed Garda Commissioner Eoin O'Duffy to the army command.