Me and the Iran War

As a teacher of Public International Law, I am often asked questions that if international law prohibits war, how effective is it. Is it not a weak law…Why do we have to study this law? These are fair questions. But there is more to it than just answering this in a yes, no or giving a justification that peace is the only solution and countries should refrain from war. For students who spend time studying treaties, doctrines, and reports of the ICJ, the reality of war can make international law seem powerless. The relationship between law and war has always been complex. International law does not eliminate war too.

There are some rules. The rules governing the use of force were born out of the devastation of World War II. In 1945, states created the United Nations and adopted the United Nations Charter, which established a foundational rule that states must not use force against one another.  Of-course except in self-defence or when authorised by the UN Security Council.

In theory, this was meant to prevent the kind of catastrophic wars that had defined the early twentieth century. In practice, however, international politics has repeatedly tested these rules.

Think of the Iraq War. The invasion led by the United States was justified partly on the grounds of preventing the use of weapons of mass destruction. Yet the absence of clear authorisation from the UN Security Council led many international lawyers to argue that the war violated the UN Charter. Earlier conflicts raised similar questions. The Vietnam War triggered intense debates about intervention and sovereignty. More recently, the Russian invasion of Ukraine has widely been regarded as a violation of the prohibition on aggression under the UN Charter.

This war involving Iran reflects the same legal tensions. Military actions are framed as self-defence by some states, while others condemn them as unlawful uses of force. Lawyers debate concepts such as “imminent threat” and “anticipatory self-defence,” but these legal arguments unfold in a geopolitical arena where power and security concerns often dominate. This inevitably leads to another question my students ask, “Are the rules of the United Nations failing?”

There is some truth to that concern. The structure of the United Nations Security Council allows its five permanent members, the United States, Russia, China, France and the United Kingdom, to veto resolutions. When major powers are directly involved in a conflict, the Security Council often becomes paralysed. We saw this during the Syrian civil war, when repeated vetoes prevented stronger collective action. Similarly, during the ongoing war in Ukraine, Russia has vetoed resolutions condemning its own actions.

This structural limitation exposes one of the fundamental weaknesses of international law: its enforcement depends heavily on political will.  Unlike domestic legal systems, international law lacks a central authority to enforce its rules. Institutions such as the International Court of Justice and the International Criminal Court rely largely on the cooperation of states. When powerful states refuse to cooperate, enforcement becomes extremely difficult.

But to conclude that international law is irrelevant is not right. Even powerful states rarely claim that law does not matter. Instead, they attempt to justify their actions within legal arguments. They invoke self-defence, humanitarian intervention, or collective security. This constant search for legal legitimacy shows that international law still shapes global expectations.

History also demonstrates that legal accountability, though often delayed, can emerge from conflict. The Nuremberg Trials after World War II established the revolutionary principle that individuals, not just states, could be held responsible for war crimes and crimes against humanity. That principle continues to influence modern international justice.

When my students ask whether international law works, I can say that International law is not a perfect shield against war. It cannot always restrain powerful states, nor can it eliminate geopolitical rivalry. But it does something essential. It provides a common legal language through which the world judges the legitimacy of war and peace. Without international law, global politics would be governed entirely by power. With it, even the most powerful states must at least attempt to justify their actions before the court of international opinion.

From Ukraine to the tensions surrounding Iran, the legal framework may be imperfect. But it remains indispensable.For those of us who teach Public International Law, the challenge is not simply to defend international law against criticism. It is to encourage the next generation of lawyers to strengthen the institutions and norms that make it meaningful.

If international law sometimes fails, the alternative is a world where law does not exist at all. That will be disastrous. Because then, there will not be any law students. And no questions.