Related Rule
Ireland
Practice Relating to Rule 33. Personnel and Objects Involved in a Peacekeeping Mission
Ireland’s Basic LOAC Guide (2005) states:
[T]he role of peacekeeping troops can be compared to that of an umpire or a referee. As such, the peacekeeping troops would not be considered combatants, as this term is understood under international humanitarian law and the laws of armed conflict.
… It should not be assumed that simply because a UN Resolution invokes Chapter VII [of the UN Charter], that the offensive use of force is automatically authorised or that the UN personnel automatically become combatants. 
Ireland, Basic Guide to the Law of Armed Conflict, TP/TRG/01-2005, Director of Defence Forces Training, Department of Defence, July 2005, p. 14.