The seismic impact of Russia’s invasion has prompted a reassessment of geopolitical alliances and many countries’ security posture. The U.N. General Assembly’s vote to suspend Russia from the Human Rights Council provides some insight to the broader global picture, while Sweden and Finland’s NATO applications follow the general momentum in Europe. China’s position on the war is also a looming and sometimes ambiguous factor to calculate.

Policy positions on ideological, political, security and economic alliances are connected to, but distinct from, questions around the “law of neutrality.” When evaluating Russia’s ominous threats of deploying nuclear weapons it is important to understand the normative legal framing of neutrality that might apply. This could provide some understanding of how Putin might view, for example, the United States’ provision of $3.4 billion in security assistance to Ukraine since Russia’s February 24 invasion.

Analysts have already been clear: There is no legal justification to characterize the United States, or any other country providing military assistance, as valid belligerents using the law of neutrality. The whole story does not end here, however. Properly analyzing the issue at this consequential moment requires precision and a discourse that carefully incorporates interdisciplinary considerations. To start, it is important to quickly distinguish the law of neutrality from other forms of neutrality discussed in legal and diplomatic circles.  

Examining the Law of Neutrality

In international law, neutrality can refer to the rights and obligations of neutral states and their citizens following the outbreak of international armed conflict, as well as the terms and conditions for longer-term “neutralization” as negotiated in bilateral or multilateral treaties. States can also project their versions of neutrality unilaterally, as a matter of domestic security and political and economic policies and practices. This was the case with the United States for most of its history before World War II, following George Washington’s “Neutrality Proclamation” in 1793 amid the French Revolutionary Wars. These types of alliances and declarations also took shape most notably during the Cold War following decolonization the and the establishment of states “non-aligned” with either the Soviet Union or the United States. The war in Ukraine has major implications for the discourse around all three of types of neutrality: 1) the law of neutrality; 2) terms for the neutralized; and 3) the non-aligned. This analysis focuses on the first category.

In war, the law of neutrality creates a binary determination. Parties, by action, declaration or default, can be classified as either belligerent or neutral. Western laws and customary practices for neutral states developed in large part in the Prize Courts of 18th and 19th centuries to decide claims made by state-owned and commercial interests over property seized on the high seas. As a practical matter, the law of neutrality helped protect international trade during war. Beyond that, it served to localize war and limit its scale both at land and at sea.

The codification of these norms was embodied in treaties of the Second Hague Peace Conference (1907), in large part in the “Convention (V) Respecting the Rights and Duties of Neutral Powers in Case of War on Land” and the “Convention (XIII) Concerning the Rights and Duties of Neutral Powers in Naval War.”

A paradigm shift occurred after World War II and the establishment of the United Nations. With its roots in the Kellogg-Briand Treaty of 1928, Article 2 of the U.N. Charter provides a universally accepted prohibition on wars of aggression and demands that member states settle conflicts peacefully. Article 51 protects the right of nations to act in individual or collective self-defense. Within this new normative framing, international armed conflict only occurs between aggressors and defenders. All other force is only legitimate when conducted with Security Council authorization under Chapter 7 of the Charter or through regional organizations, as outlined in Chapter 8 and in accordance with the same principles.

As a result, over the past 75 years the law of neutrality lost prominence and some claim it to be obsolete. That said, the binary discourse of belligerent and neutral states is still wrapped in the fabric of the laws of war and neutrality principles are embedded in contemporary military doctrine.

Neutrality in the Ukraine Context

The question raised often within the conflict in Ukraine is whether assistance in the form of military aid, supplies, logistics or intelligence by NATO, its member states and their allies will give Putin a pretext to broaden the fight. At first glance, violations of the law of neutrality by countries like Poland, Romania or even Germany or the United States, could provide Putin justification for further military action beyond Ukraine’s borders, leading to catastrophic spillover into Europe. However, scholars have dismissed any such legal argument, explaining that jus ad bellum (i.e., the modern legal criteria for entering war) not neutrality law, dictates the legitimate use of force. Countries contributing to Ukraine’s self-defense are not only justified but are also arguably obligated to act. This week, the Congressional Research Service explained that the United States “ha[s] adopted the doctrine of qualified neutrality,” which permits states to take non-neutral acts in support of the victim of unlawful aggression.

While not wrapped in legalese, Putin has been clear in warning against outside interventions, this week threatening a “lightning fast” response. In the context of such threats, it is unclear what in his mind constitutes a violation and what would be the justified response. Whether constrained by liberal norms or realpolitik, Putin has yet to attack countries he sees as assisting Ukraine. While many have guessed, his real motivations remain a mystery. Lessons from history are crucial to contend with the emerging threats of an upended rules-based order. 

Neutrality’s Origins

Looking back, it was Russia, with commerce as its chief concern, that established the first League of Armed Neutrality (1780-1783), a short-lived alliance of nations responding to British violations of the established laws and customs by seizing neutral ships during the American revolution. The group sought to enforce customary principles of international law and was powerful enough to force some reform of British law. Similarly, the United States, since its founding, has advocated for the protection of the private rights of citizens from neutral states during wartime to ensure free trade with belligerent and neutral states alike.

Later opposing views on the law of neutrality came to a head during World War I, as Germany took a strong position that the neutral private trade by Americans of weaponry and supplies must be balanced between the Central and Allied Powers. The United States opposed this interpretation and allowed for the continued provisions to Great Britain and its allies. As Francis Boyle, a professor of international law, explains, “The United States government eventually responded by entering the war to secure those rights of its nationals and thus uphold the international laws of neutrality and armed conflict.” Unfortunately, sophisticated legal frameworks and institutions were not enough to prevent the outbreak of World War I.

Prior to this, notable mid-19th century military innovations — such as long-range weapons and the mini-bullet, the Gatling Gun, iron-clad warships, and naval mines and torpedoes — unleashed untold death and destruction around the world on battlefields and at sea. In response, a flurry of international humanitarian action resulted in the formation of the International Red Cross (ICRC) in 1863. Thereafter, the ICRC was central to treaties like the “Geneva Convention for the Amelioration of the Condition of the Wounded and the Sick” (1864) and the Hague Conventions (1899 and 1907), which sought to create rules for armed conflict to reduce its violent devastating effects. Following the Hague Convention of 1907, progressive and optimistic support for an international legal and normative order that maintained peace and stability was on the rise. 

In recent years commentators have compared the current era to this perilous pre-war period of the 1910s, when rising powers of Germany, Japan and the United States threatened the hegemonic British Empire. Such comparisons prompt the West to question its calculations about the norms framing the behavior of powerful authoritarian states like Russia. The war in Ukraine has served to upend all prior assumptions about the global order.

Preventing the Weaponization of International Law: What’s Next?

Over the past decade, we have seen how Russia weaponizes international laws and norms. The annexation of Crimea in 2014 was justified based on the right of self-determination, enshrined in the U.N. Charter and the International Covenant on Civil and Political Rights. The claims of genocide used as a pretext for February’s invasion revealed the depths of Putin’s cynicism. Basing such claims on doctrinal principles of the “Responsibility to Protect” are particularly rich, given the primacy Russia placed on sovereignty in its support for the atrocities committed in Syria.

Scholarly conclusions and unilateral interpretations are not sufficient to reach a stabilizing consensus among concerned states. Multilateral support for Ukraine must account for the complexity of Putin’s security, political, economic and ideological considerations. We are at an inflection point for the global order. To find solutions to these intractable issues in the U.N. Security Council and renewed calls for militarized defense postures around the world, a deeper debate on agreed legal norms is needed.

The Ukraine war has catalyzed a renewed conversation about the concept of neutrality in international law and the need to update it for a modern context. Still there are other, less salient but important reasons to update what neutrality means. Just as military innovations in the mid-19th century galvanized the world to reconsider humanitarian action, this reassessment of neutrality should reckon with modern warfare over a century after the Hague Conventions.

Ultimately, the international community needs to formulate legal norms that prevent autocrats like Putin from exploiting them to suit their own ambitions and circumvent the international laws of war. It should be unambiguous that those providing aid to Ukraine are not belligerents and any new form of neutrality must take this into account, lest the next aggressor attempts to exploit this concept. The norms for neutral states in times of war must be defined and explicit.

To get there, a convening of diverse views is vital — from the West to the global South and beyond. The Ukraine war has also demonstrated the structural limitations of the United Nations — particularly the Security Council — in this debate and made clear the need for a new Hague-style conference to update and strictly delimit the normative legal framework for neutrality. While the U.N. has its own tools for developing international law, its structural limitations require a conference outside of the auspices of the global body. In the end, however, the objective would be for an updated legal framing on neutrality to be adopted and protected through the United Nations.