Noncombatants and liability to be attacked in wars

The paper assumes that some people, at least, are liable to attack in war. In a number of ways, this is an ambiguous statement, so before proceeding, I need to clarify the specific senses in which I shall generally be using the terms "liable" and "attack." When I write that "S is liable to military attack," I mean that S has forfeited his or her right not to be attacked by armed forces. Here, "liable" is used in a normative-cum-legal sense, not descriptively as it is when one says "some colors are liable to darken in perpetual shade," and "attack" is used passively, as an equivalent of be attacked. Colloquially, then, "S is liable to attack" means roughly that S is a legitimate target. Given this, it should be clear that when I talk about the criteria of "liability to attack," I am talking in effect about the features separating people who may and may not be attacked. Unless I indicate otherwise, I also mean to focus on intended, as opposed to incidental, attacks. Finally, although "attack" often implies initiation of a conflict ("I didn't attack him! He started it!"), it does not do so here. An unjust aggressor who initiates a conflict can be, and indeed very often is, liable to attack. All of these stipulations conform, I think, with recent literature on just war.