43 Since, because of the unique conditions of their way of life, the spiritual care of military personnel requires special consideration, there should be established in every nation, if possible, a military vicariate. Both the military vicar and the chaplains should devote themselves unsparingly to this difficult work in complete cooperation with the diocesan bishops. Diocesan bishops should release to the military vicar a sufficient number of priests who are qualified for this serious work. At the same time they should promote all endeavors which will improve the spiritual welfare of military personnel.
Source: Christus Dominus (Vatican.va)