Iran's Proxy War in Yemen and International Law

Introduction and the Problem of Proxy War

A proxy war is a conflict in which two powers use third parties as substitutes for fighting each other directly. Although the legal framework surrounding proxy war is murky, there are a number of examples of such conflicts throughout history, such as the Iran-Contra Affair during the 1980s. In that case, the United States armed and trained rebel groups in Nicaragua in an attempt to overthrow the socialist government. The Nicaragua case is apropos of any discussion on proxy warfare because Nicaragua successfully sued the US in the International Court of Justice, which found that the US had violated Nicaragua's sovereignty by supporting the rebels against the state. In spite of that ruling, proxy wars continue—and what is needed is some clarity on when it is legal to provide support and when it is not. One modern example of a state involved in proxy warfare is Iran in Yemen. Iran claims to be supporting a rebel group against an illegitimate government. Critics argue that Iran is seeking to expand its hegemony in the region. Indeed, it is a common refrain among critics that proxy war is simply a way for Great Powers to avoid taking responsibility for their actions, as they can distance themselves from the fighting by using surrogates. Nonetheless, proxy wars have played a significant role in international relations, and their legal status will continue to be debated by scholars and policymakers alike.

This paper shows how the Nicaragua case can be used to help frame the issue of proxy war legality by applying it to a modern example of proxy warfare currently conducted by Iran. Nicaragua represented this issue head-on and put forth an influential opinion on how governments can violate UN Article 2(4) by supplying rebel groups seeking regime change—which led directly back into questions about whether such actions are ever justifiable under any circumstances at all. The Court awarded damages against America for interfering in another state's affairs, despite there being no formal agreement between both sides beforehand regarding who would assume control once the conflict began.

The international order needs some guidance on the matter of proxy war, as states vie more and more openly by way of third parties. When is it legal, and when is it illegal? How can it be viewed with respect to the UN Charter and the Nicaragua case? What can one learn from Iran's current example of proxy war? Proxy war has negative connotations—Mumford described it as "war on the cheap"—and it is hoped that by giving proxy war some validity it can be better regulated within an international system of law and order. This paper addresses these questions, first by examining proxy war, then by looking at the Nicaragua case and applying it to the Iran situation to help bring to the fore a framework for determining legal proxy war from illegal proxy war.

Proxy war is an armed conflict between two actors or states, fought on behalf of other parties who are not directly engaged in the armed conflict. Proxies are typically supported by the other parties via funding, arming, training, or some other form of assistance. One major problem with proxy warfare is that it blurs the line on international law regarding the arms trade.

There is no legal framework specifically for proxy war. However, there is sufficient legal foundation in the UN Charter to indicate the extent to which proxy warfare might be deemed legal. As proxy wars are often fought in support of one party to an armed conflict by another party not party to the conflict, the supporting party should only legally provide financial, material, or military support on the grounds of self-defense. This would ensure that the legality of the action is in keeping with the Charter—specifically with Article 51 and Article 2(4)—while remaining ostensibly uninvolved in the conflict itself.

Proxy war conflicts have been increasingly prevalent since the Cold War ended, as superpowers have resorted to surrogates to fight their battles for them. Examples include the Iran-Contra Affair, in which the United States supported right-wing rebels in Nicaragua, and the Soviet Union's support for communist regimes in Africa and Asia. Proxy warfare persists, often in an illegal manner, because there is no specific legal framework governing these activities, as they fall outside the scope of traditional international law and are not mentioned directly in the UN Charter. This lack of legal regulation leaves proxy wars open to abuses, such as the use of child soldiers and other human rights violations. As proxy wars become increasingly common, it is important to consider how best to regulate them in order to protect civilians and ensure that they are conducted in a manner consistent with international law.

The UN Charter and the Prohibition on Force

UN Charter Article 2(4) prohibits UN members from using force against other states. The UN Charter was drafted in the aftermath of World War II in an effort to maintain international peace and security. In order to further this goal, the UN founders decided that member states should refrain from using force against one another. While Article 2(4) does not completely prohibit the use of force, it does require UN members to exhaust all peaceful means of resolution before resorting to force. Furthermore, any force used must be in self-defense or authorized by the UN Security Council. As a result, UN Charter Article 2(4) is a key provision in maintaining international peace and security—but, as shall be shown, it is not without its weaknesses.

As Macdonald notes, such is the power of Article 2(4) that "soon after 1945 there emerged among both states and publicists a strong consensus that Article 2(4) reflected customary international law." Moreover, by 1966, the International Law Commission held the opinion that the principle of Article 2(4) "had been incorporated into the corpus of customary international law, and the provision was bodily incorporated into many treaties and other documents of the period dealing with the use of force." The General Assembly's Declaration of Principles Concerning Friendly Relations and Cooperation among States explicitly underscored this principle when it stated in 1970 that "Every State has the duty to refrain in its international relations from the threat or use of force…. Such a threat or use of force constitutes a violation of international law and the Charter of the United Nations and shall never be employed as a means of settling international issues." The matter could not be clearer: the international order in the post-war period is based on a principle of force for defensive purposes only—never for coercive purposes.

It is thus evident that the UN Charter was written with a non-interventionist principle at its core, meaning that states should be focused on keeping the peace rather than on neocolonialism, expansionism, or interference in other states' affairs of government. Essentially, the UN Charter also set the stage for a clash between idealism and realism. After World War II, interventions lost the colonial framework that had previously supported them. As Farer points out, in today's world "a consensus concerning the characteristics of intervention begins to crystallize only when one state seeks to affect the 'authority structure' of another state rather than specific policies; when, in other words, the coercion is directed at the identity of policymakers or the processes of policymaking." In accordance with their UN obligations, states are not to interfere in other states' governance—directly or indirectly. Direct interference is typically obvious enough and precipitates blowback. Indirect interference, however, may be conducted in hopes of reducing the risk of blowback, and it is here that proxy war comes into play. Proxy warfare represents the face of stark realism in a world where the international order is decidedly rooted in a post-war ideal.

At the heart of the UN's principle of peace is Article 2(4), a cornerstone of the UN's peacekeeping efforts that has been invoked numerous times in response to armed conflict. Because the article does allow for the use of force in self-defense or when authorized by the UN Security Council, problems have arisen—for instance in the Nicaragua case, where the Court found the US at fault but the US, through the UN Security Council, effectively overturned the judgment. At the core of the Nicaragua case was the problem of two superpowers fighting in the backyard of a third state. When wars between the Great Powers are waged, proxy warfare is often an outcome. One consequence of proxy warfare is a lack of accountability, transparency, and rule of law.

In recent years, there has been much debate over the interpretation of UN Charter Article 2(4), particularly with regard to the use of military force. Critics argue that the article is too restrictive and prevents the UN from taking action in cases of genocide or other mass atrocities. Others argue that the article is necessary to prevent further escalation of violence and should be interpreted narrowly. The UN Charter remains an important document in guiding the UN's efforts to maintain international peace and security—but when it comes to proxy war legality it allows some gray area to persist.

Legality of Proxy Warfare and What Constitutes Lawful Assistance

To better understand this issue, closer examination of the legality of proxy war is needed. Proxy wars are not expressly prohibited by international law, but they are generally considered to be in violation of the spirit of the law. Proxy wars often result in civilian casualties and can escalate into full-blown conflicts. They can also lead to a collapse of the government or state if one side is successful in overthrowing the other. For these reasons, it is generally viewed in the international order that to engage in proxy wars is to take great risk, if not to outright flout the obligations one owes to the international order. Those who do so are often seen as acting irresponsibly.

Thus, for any proxy war to be conducted today with a view to legality, it should be understood as one in which a legitimate and lawful aim is pursued—such as providing support for a legitimate government against rebel actors through arms, training, or financing. Or, as Wright observes, proxy warfare should be considered only in the light of modern international law, which stipulates as its core fundamental principle "the duty of each state to respect the sovereignty, territory, independence, domestic jurisdiction, and self-determination of other states." International law exists as a way of codifying that principle and as a means for states to "protest against violation of that law injurious to its interest by another state." Yet articulating legality or illegality with respect to this fundamental principle remains controversial, because parties may see justification and adherence to the principle where there is none, or where other parties see violation.

Proxy wars have been a mainstay of international relations for centuries, but their legality has long been questioned. In the Middle East, for example, one finds states supporting armed rebels against the Syrian government, states supporting the Yemeni government against Iran-backed Houthis, and other instances. According to international law, and Article 2(4), it is a violation of the sovereign rights of both countries involved when support is given without consent of the governed state or for a purpose unrelated to self-defense. However, many countries have engaged in proxy wars throughout history because they believe they are fighting a greater evil by opposing an entrenched government—indeed, this was the argument of the US in Nicaragua. Or they engage in proxy warfare because it tends to be off the public radar and therefore less likely to upset voters. Identifying where legality exists is therefore difficult because of the extent to which justification can be given—if not in one international court, then certainly in a Security Council.

Some discussion of the ethics of intervention via proxy is also needed. Pfaff points out that the benefactors of proxy war have a responsibility to establish the justice of their intervention and that their intervention should be in keeping with the peacekeeping directive of the UN Charter: "What differentiates the ethics of proxy war from the traditional ethics of war is the additional considerations the benefactor must undertake not only in establishing the justice of its cause but also regarding the management of the moral hazards to which the proxy relationship gives rise. The addition of a benefactor in an otherwise local conflict not only raises the stakes for local actors; it can change the stakes for non-local ones as well. As the stakes change, so does the willingness of these other actors to get involved and become benefactors themselves. As they do get involved, divergent local, national, and international interests come into play making favorable resolution of the conflict difficult if not impossible." In other words, benefactors of proxy wars must not act like Great Powers seeking to assert their own expansionist or neocolonial ambitions on weaker states via proxies. Such would be unethical and essentially illegal.

The proxy war between Iran and Saudi Arabia playing out in Yemen helps to show the complexity of the issue. Saudi Arabia has been providing military support to the Yemeni government, while Iran has been backing the rebel Houthi movement. Both sides claim justification. Thousands of civilians have been killed in the resulting conflict, and there is no end in sight because for the participants it is about self-determination. Given the death and destruction that proxy wars can cause, it is clear that they are not in line with the spirit of international law as laid out in the UN Charter. However, as long as countries continue to engage in this type of conflict, the question of their legality will remain open.

Proxy wars are often seen as a way to avoid direct confrontation between the parties involved, and as such they can be considered legal under international law only when the matter at stake is self-defense. Can both sides in a proxy war lay claim to an issue of self-defense? It is plausible that they could; thus, a better framework is needed to clarify which actors are antagonists and which are acting to defend themselves. There are certainly situations in which proxy war could be considered unlawful assistance, but since there is no legal definition of proxy war, general understanding of the term and parameters for judging it are needed. That is why the case of Nicaragua is helpful in assessing modern proxy wars and their legality.

Wright identifies a number of general principles that should be kept in mind when appraising the legality of methods employed as part of proxy warfare. These principles include the following: persuasion is legal; coercion is illegal and military action is to be considered coercive; "declarations by governments of ultimate purposes are legitimate, and coercive acts to implement them are illegitimate"; "acts of government agencies are attributable to the state and acts of private individuals are not, but the complicity or negligence of a government may render it responsible for the latter"; acts of self-defense are legitimate and legal; injuries to states or agents abroad or contempt for the rights of sovereign states are illegal; "invocation of a competent international agency to settle disputes" is lawful but must not invade the domestic jurisdiction of a state; "civil strife or other revolutionary or violent action within a state's territory is within its jurisdiction, but if such strife is stimulated by external intervention or is likely to develop into international hostilities, the United Nations may intervene." The main themes guiding these principles are respect for state sovereignty, commitment to using force only for self-defense, respecting international law and its courts and agents, and respecting the role of the UN in keeping the peace.

In some instances, one side may provide military assistance to a proxy force in the form of weapons, training, and funding. This is what could be described as legal assistance so long as it falls under the necessary conditions of self-defense. Legal assistance can help a proxy force to be more effective in battle and ultimately increase the chances of victory for the sponsoring nation. At the same time, there are risks associated with legal assistance in proxy war. If the proxy force is defeated, for example, the sponsoring nation may be drawn into direct conflict with the enemy. Additionally, legal assistance can sometimes lead to a slippery slope, whereby a nation becomes increasingly involved in a conflict it had originally intended to stay out of. Thus, legal assistance in proxy war is a risky but potentially advantageous strategy; it is important to weigh the risks and benefits carefully before deciding whether to provide such assistance.

Unlawful assistance could be considered an overstepping of bounds for an expansionist agenda. If a party provides military support to another party with the intention of furthering its own interests rather than those of the party it is supporting, this could be considered unlawful assistance. Additionally, if a party provides military support with the intention of destabilizing a region or toppling a government, this could also be considered unlawful assistance. The goal of the international order is to maintain international peace. As Rowles points out, "while the avoidance of war remains the principal reason for controlling the use of force across international frontiers, it is also important to appreciate the consequences of a climate of military insecurity fostered by the failure to uphold the legal prohibition against force."

The International Court of Justice's ruling in Nicaragua v. United States created a precedent that has been cited in subsequent cases, such as Iran v. Iraq (1980) and Sudan v. Ethiopia (1988). While proxy war is not explicitly prohibited by international law, states must be careful to avoid infringing on another state's sovereignty when providing assistance to rebel groups. Nicaragua alleged that the US had violated its sovereignty by funding and supporting the Contras, a rebel group fighting against the Nicaraguan government. Specifically, Nicaragua charged "that the policy and actions of the United States in supporting a mercenary army, the contras, in launching attacks on the territory of Nicaragua, and in seeking to overthrow the government constitute the use of armed force against Nicaragua in violation of the international obligations of the United States under the UN Charter." In its defense, the US claimed that it was providing Nicaragua with "legal assistance" in its fight against communism. The Court ultimately found in favor of Nicaragua, ruling that the US had violated Nicaragua's sovereignty and that Nicaragua was entitled to receive compensation for damages caused by the US intervention.

Conclusion

The foundation for a legal framework guiding nations on the legality and illegality of proxy warfare exists in Article 2(4) of the UN Charter, but the Nicaragua case shows full well why more is needed than a mere legal framework. Enforcement is nine-tenths of the law, as the saying goes. In order to really maintain the international order and peace, the UN Security Council needs to be overhauled and reformed to ensure greater equity among the member nations, and also to ensure that military force can be used against offending states that choose to violate Article 2(4) via proxy warfare.