If you want to study some very interesting information go to Winchell Chung's Project Rho site.
This section will discuss and illustrate some fundamental concepts about fighting wars in space. At this point in history, any apparent knowledge of how to make war in space is educated speculation at best. I offer my opinions, based upon much study and the use of technical imagination.
Most so-called "Military Science Fiction" relies on one or more fundamental departures from what is now commonly accepted in the scientific community as the "Laws of Nature". Hopefully I can shed some light on the presumptions made in science fiction narratives as well as the assumptions regarded as fact within our limited "scientific" knowledge. No doubt, if we ever get there, space exploration and warfare will be rather different than what has been expounded for decades now. We never know when a new technology may present itself and/or be adapted to an application which manifests revolutionary impact on the existing paradigm.
The prerequisite to Interstellar Warfare is becoming "interstellar". This requires the capability to move populations and infrastructure to other star systems. The current paradigm is bent on achieving the capability to actually get hardware to another close star system. Once that is proven in principle, the population can follow. Meanwhile the people of Earth will be exploring and developing the consumption of resources in our own local star system which we now call the "Solar System". Eventually that effort and the knowledge gained will lead to the first interstellar mission.
Such a mission will require the combination of a population and infrastructure capable of long term existence with the additional resources to be capable of initiating complete exploration of the target star system and development of planetary habitation if possible. Once the mission arrives, using whatever method of transportation available at that time, long term prospects for survival and sustenance will quickly become evident. Initial steps will probably entail finding a stable orbit for the transport vehicle which now must become a space station.
Eventually the new star system will become familiar and some planetary bodies may even be explored using robotic expeditions and later manned missions. Mining and industrial expansion should be the first goal in order to continue the expansion of infrastructure needed to accommodate the growing population base. The discovery of an inhabitable planet would be a major milestone along the path to establishing a long term sustainable civilization. Meanwhile, communication of this information to the home star system (Sol/Earth) will be used there to improve methods and define scopes for follow on mission hardware and population.
This progression will be repeated as additional star systems are explored and settled by the human race of Earth. Sometime during this long process several things could happen that lead to hostility between star system populations and/or groups of developed star systems. There might even be an encounter with non-human sentient beings having higher technological capability. Such an encounter would most likely trigger a unifying force upon the growing human populations in the several settled star systems of humanity.
One way or another there will eventually be some hostile action on the part of alien, criminal or socially rebellious populations that will require military action between forces from separate star systems. Thus the initiation of Interstellar Warfare.