At a strategic level the agreement demonstrated that the British recognised as legitimate the wishes of the Republic to have a direct interest in the affairs of Northern Ireland. It also demonstrated to paramilitaries that their refusal to negotiate with the governments might be self-defeating in the long run. Unlike the Sunningdale Agreement, the Anglo-Irish Agreement withstood a much more concerted campaign of violence and intimidation, as well as political hostility, from unionists. However, unionists from across the spectrum felt betrayed by the British government and relations between unionists and the British government were at their worst point since the Ulster Covenant in 1912, with similar mass rallies in Belfast. Unionist co-operation needed in tackling Republican violence became so damaged that in 1998 Margaret Thatcher said she regretted signing the Agreement for this reason. Republicans were also left in the position of rejecting the only significant all-Ireland structures created since partition.