In this context, they embarked on the policy of planning, together with the Irish authorities, for the defence of the island. This was a controversial proposal as most of the Irish political establishment had been combatants in the Anglo-Irish War against the British between 1916 and 1921. For instance, the Fianna Fáil politicians in the Irish government included Éamon de Valera, Seán T. O'Kelly, Seán Lemass, Gerald Boland, Oscar Traynor, Frank Aiken, Seán MacEntee, and Thomas Derrig, all of whom had been active against the British. On the British side, Winston Churchill, and many senior members of his administration had forcibly opposed their bid for an independent Irish state, including setting up the controversial Black and Tans to oppose militant separatism.