National security within the framework of constitution and legislation

National security is the most important element that takes part in the concept of state and ensures the survival of the country and sovereignty elements against internal and external threats. States use many power elements for the realization of this purpose, especially political, economic and military power. National security is a multi-functional area in terms of the practices that states perform while maintaining. State of emergency such as mobilization, warfare, epidemic disease or severe economik crises; fight against terrorism, which gained a new dimension after September 11, 2001; ensuring border security against external threats and dangers within the land, air and sea sovereignty area; cyber security in terms of software and also hardware in the field of informatics and technology; elimination of cross-border threats in the light of the concepts of "prevention and preemption" which we encounter as a new phenomenon within the scope of legitimate defense in terms of the detection, diagnosis and early intervention of external threats are the leading national security practices. States do not have unlimited powers on practices carried out in order to ensure national security. National and international regulations form the limit of national security practices. While recognizing the right of the states to legitimate self-defense in ensuring national security, the globalized world order, emerging asymmetric threats and hybrid operational enviroment have made global or regional treaties or conventions, especially United Nations and NATO founding treaties, as important legal bases.