What is Government?
Rand discusses this topic in "The Nature of Government" in "Capitalism: The Unknown Ideal".
Earlier I've discussed the epistemological need that government is supposed to be able to satisfy. Before going on, I think it's important to look at the concept of government in more detail. What attributes are common to governments? What attributes are necessary for a proper government? What exactly is a government?
Governments are usually divided into three major branches -- the Legislative, the Judicial, and the Executive. This division is based on function, with the three major functions of a government identified.
The Legislative branch makes the decision on what kinds of actions are permissible in its jurisdiction. In a proper government where the protection of individual rights is the fundamental goal, this would involve identifying what constitutes an initiation of force, and what kind of response is appropriate to it. It would involve establishing the method by which a use of force is to be evaluated. It's job is to determine the general rules and principles that govern the use of force in society.
The Judicial branch of government is responsible for applying these rules and principles to specific cases. It is responsible for judging the use of force in society and deciding what kind of responses are appropriate. The goal here is not just to identify whether a use of force was an initiation or merely retaliatory. Anyone could make that judgment. The Judiciary has to accomplish this through very rigidly defined means to ensure that objective methods were used.
Both the Legislative and Judicial branches of government, in their own ways, deal with the epistemological need identified earlier. They decide what is an appropriate use of force in the general sense, and in the specific sense. They determine what is an appropriate response as well.
The Executive branch is responsible for enforcement. It typically involves arresting criminals, punishing criminals, and protecting the nation from outside invasions. The Executive branch is responsible for actually implementing the retaliatory force. They're the muscle of the government, the ones actually responsible for making sure the decisions are implemented. Without the means to back up their judgments, the other two branches are all talk.
The proper goal of a government is to protect individual rights. Not all governments do this, or even recognize this as a goal. But they still have features in common. The concept of government needs to be defined widely enough to include even illegitimate governments. To make it more general, a government decides what kinds of actions are permissible, and what are the punishments for acting in an impermissible way. It establishes methods for determining these rules, and methods for implementing them. And of course, it makes sure they get implemented.