The war was prosecuted ruthlessly by the Irish Republican Army which, paralleling the political efforts of Sinn Fein, hoped to break Britain's will to rule Ireland and create an independent Irish republic. The British retaliated by introducing two new irregular forces into Ireland, the Black and Tans and the Auxiliaries. Fighting took place principally in counties Cork, Limerick, Tipperary, Monaghan, Armagh, Clare, Kerry, and Longford. It was sporadic but vicious, with fewer than 2,000 IRA volunteers facing over 50,000 crown forces. The IRA depended upon energetic local leaders -- where there were none, there was little fighting.