Although national security is a prerequisite for the development of any state and the well-being of its citizens, it is nevertheless characterized by a multitude of biases that have almost exclusively associated it with the restriction of human rights and fundamental freedoms, giving it a negative connotation.

The Armed Forces play a crucial role in defending a state's national security, usually being used – due to the adverse consequences of the use of armed violence – by the political leadership only when vital national interests are threatened.

However, the use of armed violence is related to a multitude of parameters that allow for its examination from various perspectives, according to the theoretical background of different scientific fields. The purpose of this book is the interdisciplinary study of the use and threat of armed violence from the standpoint of International Relations, Strategy, Military Science, International Law, and National Security.

Through this approach, an attempt is made to clarify the relationship between national security and armed conflicts, which to this day remain a (undesirable but real) means of resolving disputes between state and non-state actors, confirming Winston Churchill's view that: "The history of the human race is war."

In this way, the existing literature related to armed conflicts is enriched – as this book presents the principles, categories, actors, means, methods, and tactics encountered in modern armed conflicts – and a strategic analysis is conducted of the events that took place in Afghanistan, Ukraine, Nagorno-Karabakh (Artsakh), the Gaza Strip, and the broader Red Sea region.

At the same time, a significant gap in Greek literature regarding Security Studies is addressed, while also highlighting the timeless importance of security, which Thomas Hobbes emphasized as early as the 17th century: " […] without security, there is no room for industry [...] there are no arts, there are no letters, there is no society, and worst of all, there is continual fear and the danger of violent death; the life of man is solitary, poor, nasty, brutish, and short."