This work concerns a comparatively unexplored area of New Zealand military history- Aid to the Civil Power (ACP). ACP is divided into three distinct forms. The first is Military Aid to the Civil Conmunity (MACC) which covers areas such as disaster relief and civil defence. MACC is not examined in this thesis. The other two forms are Military Aid to the Civil Ministries (MACM) and Military Aid to the Civil Power (MACP). MACM is the use of military personnel to replace striking workers. MACP is the use of military personnel to support the police. Three specific incidents are studied and these are the 1951 Waterfront Dispute (MACM), the Cook Strait airlifts (Operation Pluto, MACM) and the 1981 Springbok Tour (MACP). Within these incidents the following areas are explored; civil-military relations and civilian control of military operations, the law, how governments justify ACP operations, the public reaction to ACP operations and, lastly, the military response to ACP operations. The study establishes the following hypotheses. Firstly, civilian control is the key feature of any ACP operation as it ensures that the government is seen to be governing. Secondly, the present laws relating to ACP confer uncertain responsibilities and powers on both the police and the military. As a consequence there is a possibility of an ACP operation being conducted that contravenes the government's wishes. Additionally, the newest piece of ACP legislation, the International Terrorism (Emergency Pcwers) Act 1987, lacks focus and clarity and this has ensured that the act is a poor replacement for the PSCA. Thirdly, governments have undertaken ACP operations to gain political capital. In justifying these operations various governments have portrayed their actions as upholding the public good although their level of commitment to the public good sometimes appears questionable. Fourthly, the public response to an ACP operation is dependent on the incident and not the principles involved in ACP. This lack of an underlying philosophical basis to the response explains the rapid shifts in public opinion that have occurred. Fifthly, the armed forces show a great reluctance to become involved in any ACP operation that could result in conflict with the public. This shows an awareness on the part of the military of the importance of civil-military relations. The thesis concludes with a discussion of future trends in New Zealand ACP operations. It is considered that MACM will become a less viable option as society becomes increasingly technological. This is because the armed forces can really only supply labour as modern society and the military have few skills in common. Additionally, society is less labour oriented than it was in previous decades. The prospects of MACP operations being conducted in New Zealand are considered remote given the current lack of violence in New Zealand political life and the success of the police in dealing with disorder.