Armed conflicts of the 21st century show that the international legal order is under pressure. Great powers violate the obligation of jus contra bellum protected by Article 2 (4) of the UN Charter. While the general ban on the use of force and international humanitarian law is still in force and applicable, the law of neutrality is gaining significance as well.

Armed conflicts of the 21st century seem to question the foundations of international law. Violations of jus ad bellum are named and aggressors are called upon to keep adhering to their obligations under the UN Charter. International law seems to be powerless and ineffective against the gravest legal breaches.

One interesting aspect of these dark times is the possibility of the resurgence of the status and law of neutrality. With the United Nations Security Council (UNSC) unable to act against violations of international law and acts of certain states endangering international peace and security, other tools of international law may gain priority.

Switzerland is the model of permanent neutrality. Its neutrality was confirmed by the Second Treaty of Paris on the margins of the Congress of Vienna, and many other states followed its example later in history. The law of neutrality was mostly codified by the 1907 Hague Conventions, and further regulated by other norms of international law, like the 1949 Geneva Conventions. A state can decide to be neutral towards a specific international armed conflict on an ad hoc basis as well, by simply abstaining from it. The most important obligation of a neutral state is to abstain from the international armed conflict, not influence the outcome of the conflict by economic, military or other means and to treat parties to the conflict without discrimination. Belligerents of the international armed conflict have to respect the neutral status of a state abstaining from the conflict in question, however, they have to respect the territorial integrity, impartiality and other rights connected to neutral status of the state in question as well.

There is an ongoing debate regarding the relationship of the law of neutrality to jus contra bellum. Many scholars ask the question, whether neutrality is obsolete. After the adoption of the UN Charter, does neutrality even exist? 

Since the UNSC is unable to solve certain ongoing armed conflicts and to deter the aggressor from committing aggression, permanently neutral states may help to stop the conflict from spreading (as it was the goal in the 19th century as well) and through the policy of positive neutrality, try to help with negotiations and further actions with a humanitarian aim. This may include diplomacy, trying to bring the parties together to agree to end the conflict and adopt a peace treaty, provide humanitarian aid for victims, support the International Committee of the Red Cross in conducting humanitarian activities in territories affected by the international armed conflict, etc.

Thus, neutrality can play an important role in ending the international armed conflict and mitigating human suffering stemming from it. Since the UNSC failed to restore peace and security with regard to some international armed conflicts and the crime of aggression has not been sanctioned yet through international law, another layer of international law gains importance.

The relationship between the law of neutrality and jus contra bellum leads to further questions. If the aggressor state violates the general ban on the use of force (Article 2 (4) UN Charter), may the neutral state aid the victim of aggression and take steps against the aggressor?

Currently, there is an academic debate regarding the development of the concept of the so-called qualified neutrality, which allows derogations from obligations of the law of neutrality in case the neutral state takes actions against an aggressor. The debate seems to be ongoing, however, in my opinion, we are currently witnessing the formation of a new norm of customary law, dynamically developing. We will see if through state practice and opinio juris a new norm of international law will emerge.

Furthermore, according to some authors, aggression as an erga omnes violation can lead to the adoption of restrictive measures (’sanctions’) against the violating state by any state. This could mean that they can be adopted even by a neutral state. This does not mean that neutral status ceases to exist or it is undermined; the neutral state can be mindful and conduct a successful neutrality policy balancing out different obligations and goals under international law.

Neutrality not only still exists in the 21st century, but it serves humanitarian objectives, neutral states strive to aid with ending armed conflicts and isolate them from spreading. Neutrality is not suitable for any state, assuming neutral status is based on history, geopolitics, security policy and the majority view of the society of the state in question. With the UNSC being unable to avoid or sole certain international armed conflicts, the role and function of neutral states gained a new impetus in the 21st century.

Árpád Lapu is an assistant research fellow at the Károli Gáspár University of the Reformed Church in Hungary. He was a policy adviser on constitutional issues at the European Parliament between 2019-2024. He worked as an adviser at the Ministry of Justice of Hungary (2017-2019) and the Ministry of European Union Affairs (2024-2026), conducting EU law, international law and comparative constitutional analyses. He has earned his JD at the Pázmány Péter Catholic University in Hungary, has a BA in international relations from the University of Szeged, and an MA in European and international administration from Andrássy Gyula German Speaking University in Budapest. He has completed an LLM in international law at the Catholic University of Louvain (UCLouvain).