Yes, please go to the free, online Stanford Encyclopedia of Philosophy and see the entry: TERRORISM. There is a good survey of the terms, concepts and work that philosophers have contributed to. Because that will give you a full overview and guide plus recommended reading, I think it would be redundant of me to offer a great deal of material here. But I offer just a few thoughts as a preface to your looking at the Stanford entry: Philosophers have done a great deal of work on justice, law, and the use of force. You will find a great deal of this in simply pursuing the domains of political philosophy and philosophy of law, but also in the context of Just War Theory. Contemporary acts of terror / terrorism are not unprecedented historically, but as you will see in the Stanford entry, there are vexing issues in addressing terrorism within and without state sponsorship, and great differences between ostensible justifications of terrorism (e.g. nationalism, utilitarian rationale, theological warrants)...

Very compelling question. I see your point, but will try my best in response. Probably a panelist should reply who has more first-hand experience in this area (I have not yet killed anyone with chemical agents, wooden sticks, iron bars, and such), but I suspect that what makes some weapons such as chemical, biological, and nuclear weapons of special concern is that they are both more difficult to control (and hence more likely than conventional weapons for indiscriminate damage / harm) and they are part of a family of weapons that puts one on a slippery slope. So, for example, if North Korea launched a preemptive strike against the South, and the USA and South Korea in response used a small, contained nuclear bomb launched with great precision against the invaders and avoided any civilian casualties, this would open the door for the North to use a not-so-small nuclear weapon, perhaps going after civilian as well as military targets. There is another reason that may come into play: as odd as it may...

An excellent question! You are right to distinguish individual conflict from war. War seems to involve impersonal collaborative lethal conflict, though sometimes the definition of war is stretched to include a state of affairs when two communities (nation-states, cities, empires, tribes...) have declared war and so there might be a war even if the two or more sides never get around to do any actual killing. In any case, you are correct that war is not merely (though perhaps the word "merely" is not the best to use!) a matter of individual stealing or murder. Insofar as your question is more empirical than philosophical, it seems that one can make a pretty good historical argument that war is virtually inevitable. The latest thinking is that warfare probably came about approximately when we developed agriculture (on the theory that hunters and gatherers may fight as groups, but there was not quite the pressure to protect land in the absence of farms and (with surplus agriculture) you can get cities...

You make very good points! HIstorically, philosophers have been concerned about the status, importance, and duties of soldiers. Aristotle has a very high view of the warrior (and this perhaps makes quite good sense when one notes that he was a tutor of Alexander the Great) and Socrates was very concerned about not punishing (executing) members of Athens' navy who neglected to rescue sailers. Actually, Socrates' interest in soldiers is especially to be appreciated when one takes into account that he himself was a veteran (and, more specifically, a veteran of a defeated army). While there is a long tradition of philosophers reflecting on the ethics and practice of war, probably the topic was most heated recently in the 1960s and 70s during the Viet Nam War and during the Cold War. Today war seems a little less the topic of choice today (compared with the 1960s), though it is not neglected and it is not unusual to see work on international justice, nationalism, global justice, and genocide. I feel sure...