A common complaint of the moderns laws of war is that they are nothing but a set of legal hurdles that should be overcome to legitimize uses of force in the international arena. International lawyers are often accused of conducting “legal gymnastics” in order to justify a particular action. On the flip side of the same coin, some nations are accused of “lawfare,” or utilizing international law as weapon itself to seek out selfish ends.
It is, perhaps, unsurprising that this should be the case in the practice of modern international law, particularly as it relates to the use of force. The notion of what constitutes a legally permissible use of force is almost exclusively focused on objective factors. Has the United Nations authorized a use of force by whatever criteria they deem appropriate at the time? Is a nation acting in self-defense, even against a threat that is not yet fully materialized? Has another nation asked for assistance against a threat they deem to authorize a use of force? Is another nation failing to fully address a threat I deem to constitute an immediate threat?
These are all important questions to ask and should be asked prior to an international use of force. They are required to answer the requirement of a justa causa, the objective legal claim upon which a use of force could be claimed. This is a basic requirement that originated in just war theory and continues to this day. The problem, however, is that is has led to a international system where, if a legally articulate claim can be made under international law, nations feel free to utilize the use of force.
Earlier understandings of international law, however, included an additional element that is no longer included in legal calculations leading to war: animus. This element required a “rightful intention,” the subjective counterweight to the justa causa. Under this element, the use of force must be carried out with the sole purpose of correcting a larger evil and establishing a good end. Uses of force resulting from personal hatred, desire for glory, or other less noble ends were considered sinful, even if there was a valid justa causa.
The reasons for excluding animus as an element for a just war are understandable. The law is not generally fond of subjective elements, given the difficulty of proof. However, I do wonder if the absence of a subjective element has led to belief that if an objective violation can be found nations may feel free to use force when it suits their ends. Many of the greatest philosophers and theologians included the subjective notion of animus in determining right and wrong, perhaps it is time to rethink its exclusion from the law of war.