On 10 April, de Valera, having succeeded Cathal Brugha as President of the Dáil Ministry, made a formal statement of policy that referred to the Minister of Defence as being “in close association with the voluntary military forces which are the foundation of the National Army”. The word “foundation” could be interpreted as implying that the Volunteers did not at that date constitute the army of the state. In August, Cathal Brugha, now the Minister of Defence, as well as a prominent member of the Volunteers, sought to clarify this ambiguity by means of an oath of allegiance. This oath would be taken not only by all Volunteers, but also by TDs and those employed by the Dáil. While this action resolved one aspect of the problem, it further muddied the waters in terms of the line of demarcation between political and military authority.
It seems that some within the upper echelons of the IRB were initially reluctant to swear the oath, fearing that it undermined the Brotherhood’s claim to be the sole source of republican legitimacy. By degrees, however, it seems to have been near universally administered to the relevant parties, including both existing Volunteers and new recruits, over the following months. On the one hand such a step regularised the position of the Volunteers by subordinating the army to its political masters, most of whom, of course, had themselves served in the Volunteers, or continued to do so. It also, however, created the potential for a conflict between the two sides, if the Dáil could be seen as having abandoned - even temporarily - the republican position as expressed in the oath. This scenario became all too real following the signing of the Anglo-Irish Treaty of 6 December 1921 and its ratification by the Dáil the following month.