Security is a matter of high politics, central to government debates and pivotal to the priorities they establish.
Security itself a relative freedom from war, coupled with a relatively high expectation that defeat will not be a consequence of any war that should occur. (Ian Bellamy, “Towards a theory of international security”, Political Studies 1981)
A nation is secure to the extent to which it is not in danger of having to sacrifice core values it if wishes to avoid war, and is able, if challenged to maintain them by victory in such a war. (Walter Lippman, cited in Barry Buzan, People, states and Fear, 1991)
National security may be defined as the ability to withstand agression from abroad (Glacomo Luchiani, The economic content of security, Journal of Public Policy, 1989)
A treat to national security is an action or sequence of events that (1) treatens drastically and over a relatively brief span of time to degrade the quality of life for the inhabitants of a state, or (2) treatens significantly to narrow the range of policy choices available to the government of a state or to private, nongovernmental entities (persons, groups, corporations) within the state. (Richard H. Ullman, Redefining security, International security, 1983)
Security is an objective sense, measures the absence of treats to acquired values, in a subjective sense, the absence of fear that such values will be attacked. (Arnold Wolfers, Discord and Collaboration, 1962)
If people, be they government ministers or private individuals, perceive an issue to threaten their lives in some way and respond politically to this, then that issue should be deemed to be a security issue (emphasis in original). (Peter Hough, Understanding Global security, London Routledge, 2004)
Secutiry…implies both coercive means to check an aggressor and all manner of persuasion, bolstered by the prospect of mutually shared benefits, to transform hostility into cooperation. (Edward A. Kolodziej, Security and International Relations, Cambridge: Cambridge University press, 2005)