Arnold Wolfers (1952) argues that "security" is generally a normative term. It is applied by nations "in order to be either expedient—a rational means toward an accepted end—or moral, the best or least evil course of action". In the same way that people are different in sensing and identifying danger and threats, Wolfers argues that different nations also have different expectations of security. Not only is there a difference between forbearance of threats, but different nations also face different levels of threats because of their unique geographical, economic, ecological, and political environment.