Few issues in global security are as charged, or as misunderstood, as the determination of the United States and Israel to prevent Iran from obtaining nuclear weapons. To many, it looks like power politics or regional rivalry. In reality, it’s about something far more basic: survival in a world where nuclear weapons and apocalyptic ideology can collide.

The World That Shaped Our View of Nukes

To understand today’s fears, it helps to start in 1945. By mid–World War II, Japan’s military government showed no sign of surrender. American planners expected hundreds of thousands of Allied casualties and millions of Japanese deaths in a full-scale invasion of the home islands. Every serious assessment pointed to a fight to the death.

In that context, the atomic bombings of Hiroshima and Nagasaki were seen as the least catastrophic option. They forced a rapid surrender and avoided an invasion that could have been far bloodier. Under the law as it existed then, the bombings were not illegal. There were no treaties banning area bombing, no codified proportionality rules, and no legal framework for weapons of such unprecedented destructive power.

Why Those Same Attacks Would Be Illegal Today

Modern Laws of Armed Conflict (LOAC) take a very different view. Nuclear weapons are inherently indiscriminate. They cannot be directed only at military targets, they cause long-term radiation effects, and they inflict suffering on a scale that modern humanitarian law does not accept.

Today, proportionality is judged strike by strike, not war by war. You cannot justify killing hundreds of thousands of civilians on the grounds that it might prevent a larger number of deaths later. Civilian immunity is central, and nuclear weapons violate that principle by design. Under the current legal framework, Hiroshima and Nagasaki would almost certainly be considered unlawful, even if the strategic logic were identical.

How Modern Enemies Exploit the Law

Urban warfare adds another layer of complexity. Armed groups such as Hamas, a designated terrorist organisation responsible for severe harm and human rights violations, often fight without uniforms, embed themselves in civilian neighbourhoods, and use human shields. They operate from hospitals, schools, mosques and apartment blocks precisely because they know modern militaries are bound by rules they themselves ignore.

The attacker still has to verify targets, minimise civilian harm and apply proportionality. The defender’s violations do not cancel the attacker’s obligations. This creates a moral and tactical asymmetry: the side that follows the law is constrained; the side that violates it is not.

Most modern jurists accept this imbalance. They argue that weakening these protections would lead to catastrophic civilian suffering. The law is designed to restrain the powerful, not the powerless. It is imperfect, but the alternative is a return to total war.

Why Nuclear Weapons Break the Entire Logic

Nuclear weapons sit outside this framework. They are not just another tool in the arsenal. They are existential. A single detonation can destroy a city, collapse a health system, poison the environment and destabilise an entire region. Once used, the question is no longer who wins a battle, but whether societies can survive.

Deterrence worked in the Cold War because both sides wanted to live. The United States and the Soviet Union feared mutual destruction. The same basic logic applies today with other nuclear states: they may be rivals, but they are not suicidal.

The problem arises when nuclear weapons are paired with apocalyptic ideology. Elements within the Iranian regime frame history and conflict in eschatological terms. Martyrdom, redemptive suffering and the idea of a purifying crisis are not just rhetorical flourishes; they are part of the worldview. Groups like Hamas also draw on themes of martyrdom and sacrificial struggle.

Deterrence assumes that the other side values survival. But if a leadership believes that destruction can serve a divine purpose, or that martyrdom is victory rather than defeat, the entire logic of deterrence begins to fail. You cannot deter someone who is willing to burn the house down while still inside it.

Why the US and Israel Draw a Red Line at Nuclear Iran

This is the core reason the United States and Israel fear a nuclear Iran. It is not simply about regional influence or prestige. A nuclear-armed Iran would not just shift the balance of power; it would undermine the basic assumptions that have kept nuclear weapons unused since 1945.

Even if Iran never launched a nuclear strike, the mere possession of such weapons would radically change the strategic landscape. It would embolden Iran’s network of allied militias and proxies. It would increase the risk of miscalculation. It would make every crisis in the region potentially existential.

The nightmare scenario is not only an Iranian missile. It is also the possibility that nuclear materials, technology or even a device could find their way into the hands of a non-state group with apocalyptic theology and nothing to lose. A state can be deterred by the threat of retaliation against its cities and infrastructure. A dispersed movement with no capital, no conventional economy and a cult of martyrdom is far harder to deter.

The Hard Truth About Law, Power and Survival

The atomic bombings of 1945 were justified in their time because they prevented a far greater catastrophe. Under today’s laws of armed conflict, they would be illegal. Modern law intentionally restrains powerful states, even when adversaries exploit those restraints. Jurists accept this because the alternative is unregulated destruction.

But nuclear weapons break the entire system. They are strategic, not tactical. They are existential, not proportional. When combined with apocalyptic ideology, they create a threat that no legal framework can reliably contain.

That is why the United States and Israel fear a nuclear Iran. It is why they use diplomacy, sanctions, covert action and, at times, force to slow or disrupt its nuclear programme. This is not simply about dominance or prestige. It is about preventing a world in which nuclear weapons sit in the hands of actors who may not be deterred by the prospect of mutual destruction.

In that sense, the red line on a nuclear Iran is not just a strategic preference. It is a civilisational necessity.

And if prevention fails…

But this is also why appeals to LOAC ring hollow in the real world. LOAC can restrain responsible states, but it has no power to restrain a regime that already commits war crimes as doctrine. If Iran acquires nuclear weapons, nothing in LOAC prevents it from using them. The only actors bound by proportionality, distinction, and necessity would be the very states trying to stop a nuclear attack — not the regime initiating one.

And once a nuclear weapon is used, the conflict leaves the LOAC framework entirely. A nuclear detonation triggers the right of unrestricted self‑defence under Article 51 of the UN Charter. At that point, the priority is not legal theory but preventing a second strike. The likely consequence is regime‑ending retaliation, regional escalation, or nuclear coercion that destabilises the entire Middle East. This is why the world cannot simply “live with” a nuclear Iran. After the first use, every option becomes catastrophic — which is exactly why prevention, not reaction, is the only responsible path.