National security and the different modalities used by states to guarantee and promote it may be considered as a most complex responsibility of Governments. Although there are different environmental conditions attributed to this notion and there exist a variety of definitions for it, US policy-makers have expanded the transnational application(s) of this concept on a daily basis. The following research pursues the hypothesis of the existence of a direct relation between an increase in the US’ interventions at the global level and an increase in the Country’s national and international power. The presupposition however prevails that the American administration has reached consensus on the necessity of their country becoming a power in the world, despite the different political orientations each possess. Within the past two centuries, the various American administrations have shown agreement on concepts such as “security” and “national interests.” The more powerful this country has become, both nationally and internationally, the more expanded the concept of security has become for it. In addition, in the 21st century, the country’s “national” borders have gradually extended from North America to LatinAmerica and finally to all corners of the world. This article is therefore an attempt to analyse the conceptual evolution of the notion of national security in the US, within the past two centuries.
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