Proportionality in Military Force at War's Multiple Levels: Averting Civilian Casualties vs. Safeguarding Soldiers
Bohrer, Ziv, Osiel, Mark, Vanderbilt Journal of Transnational Law
C. Proportionality at the Tactical Level
Because war is littered with imponderables, it is often impossible to predict either the civilian harm or military advantage. (155) Even when the facts are relatively clear, reasonable commanders will many times differ in the relative weight they ascribe to the competing considerations. (156) The international law of in bello proportionality clearly opts for flexibility rather than invariant consistency--for a standard allowing situational discretion over any bright-line rule, whether stringent or indulgent. (157) Choosing a discretionary standard over a bright-line rule requires trust in the capabilities of the relevant actors; it also implies that a more precise norm would fail to capture the relevant situational complexities, leaving the rule either over- or under-inclusive of its purpose. (158) In the case of in bello proportionality, sweeping rules like those of Margalit and Walzer or Kasher and Yadlin cannot conceptually accommodate the need for "all things considered" judgment of the sort required by much military decision making. (159)
Margalit and Walzer, (160) as well as Kasher and Yadlin, (161) doubt whether, in the face of war's ineradicable uncertainties, complex situational judgment by commanders can often be very accurate. There is hence little need, in their view, for international law to accord their judgment so wide a berth. Both approaches therefore implicitly seek to replace complex balancing with a simpler exhortation: always prefer the lives of your soldiers over foreign civilians (Kasher and Yadlin), or almost always prefer the lives of foreign civilians over your soldiers (Margalit and Walzer). Luban, too, knows that precise numerical calculation of military gains and civilian losses is usually impossible ex ante, but nonetheless thinks that it is realistic to expect soldiers in combat, despite its stresses and epistemic limits, to apply his theory, limiting the risk they transfer onto civilians to a ratio of one-to-one. (162) Unlike the other authors, Luban thus believes that soldiers can reliably assess risks to themselves and others, i.e., they have the capacities that in bello proportionality indeed requires of them. (163)
This assumption, however, makes considerable sense only at the operational level, as will now be demonstrated. At war's tactical level, the pessimism of the other authors is, in fact, well warranted, and the applicable law must be construed to accommodate this reality, as it in fact seeks to do.
The law generally cannot expect low-echelon soldiers, making tactical decisions in battle, to fully assess in bello proportionality. That would require more expertise and knowledge than they possess. It would demand, in particular, considerable familiarity with the larger attack to which their particular battle, and their role within it, was designed in small measure to contribute. Uses of force that may appear indefensible from their local standpoint may be eminently justified from a broader perspective and vice versa. (164) The time available for tactical decision making, moreover, is usually much shorter than for an operational one. (165) Evidence also suggests that soldiers tend not to be very good at accurately assessing benefits and harms from their immediate actions. Low-ranking soldiers often get caught up in and carried away by the momentum of events. (166) This frequently leads them to overvalue the military advantage likely to result from their battlefield behavior--and hence also to undervalue the moral significance of the civilian harm likely to ensue. (167) These problems are much less acute at the operational level, where decision makers enjoy a wider frame of reference, both temporally and spatially. (168)
At the same time, completely absolving low-ranking agents from any duty to assess proportionality could lead to horrific results. (169) Under that legal arrangement, low-ranking soldiers would be duty bound to obey any order no matter how clear and grave the disproportionality of the harm expected from the action ordered. …