The principle of proportionality and business

Another principle that is key to international humanitarian law, and the third relevant principle for businesses in this course, is proportionality. Like the others, the principle of proportionality seeks to impose restrictions on what actions can be taken during armed conflict.

The principle of proportionality says that any attack, which may be expected to cause incidental loss of civilian life, injury to civilians, and/or damage to civilian objects, and which would be excessive in relation to the anticipated concrete and direct military advantage of the attack, is prohibited. This means that before any attack, a military commander must conduct an assessment that supports the conclusion that civilian losses are not expected to outweigh the foreseen military advantage. If the civilian damage is expected to be excessive, the attack should not take place. Of course, direct attacks against civilians and civilian property are strictly prohibited, so the principle of proportionality is only relevant when attacks are directed at legitimate military targets.

Much like the other principles of IHL, the principle of proportionality is not new – it has existed in various forms throughout world history. For example, in the doctrine of “double effect”, which suggests that it may be permissible to cause harm as a side effect when in pursuit of a greater good. Today though, the principle has been codified in Article 51 of Additional Protocol I to the Geneva Conventions. The principle is also recognised as a rule of customary IHL, and applicable to both international and non-international armed conflicts.

Key to this principle is the term “excessive”. How is this defined? IHL does not establish clear parameters around “excessiveness” – this is relative. However, it could be said that high value military targets will justify greater incidental harm than low value targets. For example, bombing a crowded civilian market to kill one combatant is likely to be excessive in relation to the military advantage gained, and therefore considered disproportionate. Whereas minor damage to a civilian factory built nearby a major military site may be considered proportionate.

The treaty text also provides some guidance, in that the military advantage must be “concrete” and “direct” and not merely speculative or indirect. In addition, an overarching aim of “winning the war” will not be acceptable justification. It is also important to consider the flow on effects and consequences of an attack when assessing excessiveness. For example, attacks against telecommunication networks – which may be used by both civilians and the military/armed group – does not only have the immediate effect of preventing one’s enemy from using this infrastructure, but it also has the secondary effect of adversely impacting the civilian population, including both short and long-term effects on medical services. Similarly, the principle would also apply in cyberspace. For instance, the use of malware, even if used against a military objective, may spread and cause large-scale incidental civilian damage.

The IHL principle of precautions is relevant here also. This principle dictates that parties to conflict must take constant care to spare civilians and civilian objects when carrying out operations – an attacking party must take all feasible measures to ensure that the targets are military objectives. If circumstances permit, this might require effective warning be given in the case of attacks which may affect the civilian population. Parties to a conflict must also take all feasible precautions to protect the civilian population and civilian objects under their control against the effects of an attack, for example, ensuring that military objectives are not situated in the vicinity of civilian populations.

A key differentiation between this element of IHL and human rights law, is that the principle does tolerate some civilian harm if it has been carefully weighed against the military advantage. This is where we often hear the term ‘collateral damage’ – and this is considered acceptable is certain circumstances. It is important for businesses to know this because it means that IHL may permit some harm or damage to business personnel or assets. Understanding this principle may help businesses take certain precautions when considering where to establish premises and facilities.