In a recent article, Professor Ryan Goodman puts forth a controversial argument: “war sustaining” objects in non-international armed conflicts, used to generate revenue for an enemy’s armed forces, should be targetable under international humanitarian law. In office, former president Barack Obama embraced a similar view, condoning strikes against “tanker trucks, wells and refineries,” as well as “storage sites where ISIL holds its cash.” This broad view of targetable objects is, at best, unworkable and, at worst, truly dangerous.
Donald Trump’s rhetoric has been even more concerning. He campaigned on a promise to “bomb the s— out of” ISIL. In the now famous sound-bite, he went on to say that he would also “blow up the pipes” and, generally, “blow up every single inch.” And, so far, President Trump and his Secretary of Defense, James Mattis, have kept Trump’s promise. In his first official day on the job, Secretary Mattis oversaw a total of 31 airstrikes against ISIL in Syria and Iraq.
Targeting “war sustaining” activities, even in the context of the fight against ISIS, sets a dangerous precedent and violates the established rules of International Humanitarian Law (“IHL”). Fighting ISIL is truly “one of the most complex [challenges] the world has seen in recent times,” and it should be done in a smart and decisive way. However, the claim that states should be allowed to target those activities that only contribute to sustaining the war effort of non-state groups is untenable and not the right approach. This complex and desperate fight should not be used by those in power to expand the boundaries of acceptable in-war behavior beyond what is currently permissible.
This would not be the first time President Trump alluded to violating international law. He has previously maintained that, had the U.S. “taken the oil” when it withdrew from Iraq, ISIL would not exist today. Not only is there nothing to suggest that ISIS is dependent solely on Iraqi oil, but what President Trump suggested would have been a violation of the IHL rule against pillage.
Professor Goodman’s argument, if adopted by the administration, would allow President Trump an even wider range of targets in the Middle East, likely resulting in a breach of several other IHL rules. Under Article 52 of the Additional Protocol I (“API”) of the Geneva Convention, the class of objects that can be lawfully targeted are those that “make an effective contribution to military action.” Under this definition, most states agree that only targets that make a direct contribution to military action are targetable. As Oona Hathaway writes, “[t]he weight of scholarly opinion has long maintained that [war sustaining] objects are not legitimate military targets.” Although some states have taken a broad view of targetable objects in the current fight against ISIL, many states reject the view that purely “war sustaining” objects can be targetable. Several academics have similarly rejected this view of targetable objects.
One of the biggest weaknesses of Professor Goodman’s argument is the lack of clear limiting principles. If Professor Goodman and President Obama are correct in suggesting it is legal and reasonable to target oil refineries because they generate revenue for ISIL, where do we draw the line? When taken to its logical conclusion, Professor Goodman’s argument could eventually be used to support notions of scorched earth and leave virtually nothing untouchable in war. Professor Goodman does suggests a few limiting principles: the targetable object must provide “definite military advantage,” and economic contributions that can be traced through strong connections to military action. However, even when taken together, these limiting principles cannot prevent future strikes against other objects (such as agricultural fields and factories) that might provide substantial revenue to ISIL, but that may be civilian in nature and only loosely connected to ISIL’s war activities.
An additional challenge to Goodman’s analysis, hinted at by Marty Lederman, is the complex organizational structure of non-state groups, the wide range of activities they depend on for financial survival, and the civilian nature of these activities. This poses two related issues Goodman does not anticipate.
First, if a non-state group’s sole mission is to wage war, it is easier to conclude that any and all revenue generated supports its sole function as a military group. As such, targeting activities that directly support its military actions would fall within the limitations set by Art. 52 of API. Many non-state groups that engage in war and terrorist activities, however, also operate as political bodies, engage in non-military undertakings, and may even take on governance functions. Even ISIL, a particularly vicious group engaged in truly horrific activities, has hopes of governing and growing into a formal political entity. When a non-state group is actively engaged in war, but also in the collection of revenue and taxes for the purpose of running schools, building hospitals, and providing services to a population, it becomes increasingly difficult to distinguish which revenue-generating operations support military action and what revenue is for political, civilian purposes. Research has shown that ISIL has gone “from being a purely military force to building a system that can provide basic services, such as making sure that gas and food are available, to its new citizens.” Over time, ISIL will likely evolve into “a government whose political decision-making cannot be separated from its military capabilities.” This weakens the direct connection between much of the revenue and the direct military advantage it provides. It further complicates the link between the finances and the military action, in effect rendering Professor Goodman’s limiting principles meaningless.
Secondly, even if ISIL continues its brutal regime without providing much in the way of services, the reality is that its revenues depend as much, if not more, on taxing the population it controls as they do on oil revenues. If Goodman’s argument holds, are the thousands of people ISIL is currently taxing also legitimate military targets? They provide a distinct advantage to ISIL’s military capabilities by providing the group with significant revenue. In a recent Foreign Affairs article, researcher Mara Revkin describes the story of Ahmed, an employee in an advertising agency working in Deir ez-Zor, who was forced to pay 2.5% of his income to ISIL’s bayt al-mal (the financial institution responsible for the collection of money). Ahmed’s relatively small contribution may not compare to the millions of dollars ISIL gains from oil sales, but the collective contributions of civilians (from their personal wages and businesses) can provide the organization with significant financial support. The connection between the taxes and the military advantage may be looser than that between oil revenues and the military, but ultimately, money is money, and if oil revenues can be sufficiently linked to providing ISIL a “definite military advantage,” then why shouldn’t taxes? If taxes can be traced to supporting military action, then can civilians and civilian objects be targeted as “war sustaining” activities and objects? If civilian objects and activities contribute just as much and just as directly to ISIL war activities, how can we argue these are not also legitimate “war sustaining” activities? The dangerous connection between taxing a population and their activities and their “war sustaining” capabilities leads us down a road we do not want to go.
Proponents of Professor Goodman’s theory, and perhaps Professor Goodman himself, might argue that it is not civilians like Ahmed who should or will be targeted, but rather the bayt-al-mal. Even if this may be the case, the argument remains problematic. First, this proposition raises the same issue of unclear links between the revenue and the war activities. If there is proof that all the revenue collected is indeed used to support ISIL’s military campaign, attacks on the financial institution may be permissible under Art. 52 of API. However, the revenue collected could very possibly be used for entirely civilian purposes: building schools, roads, and hospitals. If this is the case, we are back to the same problem discussed above. Secondly, pushing the boundaries of acceptable targets in war will likely create a precedent for targeting clearly civilian activities and objects. Ahmed as an individual may not yet be considered a target, despite the tax revenue he provides to ISIL, but a group of civilians, or a business run primarily for civilians and civilian purposes, could fall under the broader category of targetable objects Professor Goodman proposes.
It is easy to be sympathetic to Professor Goodman’s argument. Proposing a way to weaken one of the most terrifying groups we have ever encountered is an important endeavor. The complications raised by the ISIL example, however, illustrate the dangerous logical end to this argument. If ISIL depends on revenues from taxes and civilian activities just as much as it does from oil revenues, the United States runs the risk of creating a precedent where civilian objects and actions are also considered “war sustaining” and thus targetable. Defeating ISIL should be a priority for any government, but it should not be done at the cost of risking civilian lives and it should not serve as the basis for setting such a dangerous precedent.
 The categorization and definition of types of armed conflict is complex and beyond the scope of this paper. For more on this, see ICRC Opinion Paper, How is the Term “Armed Conflict” Defined in International Humanitarian Law?.
 For the purposes of this piece I will be referring to the Islamic State of Iraq and the Levant as ISIL. The group is also often referred to as ISIS and IS.
 See, e.g., HPCR Manual on International Law Applicable to Air and Missile Warfare (2002) (arguing that the connection between revenues generated from oil exports and armed conflict is “too remote” and thus rejecting the “war sustaining” argument); Tallinn Manual on the International Law Applicable to Cyber Warfare (2013) (stating that it would be unlawful to launch cyber-attacks on a state’s oil export industry even if the war effort depended on revenues from oil sales).
 “Because ISIL, unlike al Qaeda, is not exclusively a military organization—it holds territory and engages in at least some ‘civilian’ governance functions—the targeting of these facilities and stockpiles raises important issues under the laws of armed conflict.”