Every animate species engages when necessary in conflict with others of its kind and with other species. Most of this arises from the primal need to survive and the urge for procreation to continue the species. Whereas animals fight other animals because of instinct driven by genes, humans plan and deliberately set out to achieve domination over other humans for many purposes using lethal weapons of ever greater efficiency. Warfare is where this characteristic is brought to its ultimate extension, and combat is the locus within war where the killing is carried out. Whether or not the waging of war and combat is an innate characteristic of humans is not addressed in this work.
Warfare is accepted and legally sanctioned in human society, at least for defensive purposes.
And since the history of the species has demonstrated that wars have arisen time and again despite attempts to end them, warfare, and combat as its cutting edge, are important subjects for study. By the term military conflict we mean an antagonistic situation between two or more parties in which military forces and weaponry of each of the parties are used or are available for use if needed. Thus paramilitary units that may be created without a formal tie to a recognized political entity are military forces that can engage in military conflict, often but not always localized and limited in scope and sometimes carried out under covert or overt sponsorship of a nation. Similarly, counterinsurgency and counterintelligence forces engaged in defense of a political entity are military forces within our meaning. In the more general case, military forces are responsive to nation states and are formally organized by those states into units with weapons and uniforms.