There is no such thing as a “small” nuclear war. Even limited use would trigger mass death, famine and global collapse.

As West Asia stumbles towards a ‘small nuclear war’, it is time to evaluate the consequences for the entirety of humanity and the Planet.

A small nuclear war, by definition, is one involving the use of so-called tactical or battlefield nukes, low yield weapons (1000-50,000 tonnes of TNT equivalent) designed chiefly for a military objective, delivered as aerial bombs, shells, small missiles, torpedoes, mines etc. It does not involve the use of ICBMs, MIRVs, “city busters” and large-scale strategic weapons.

For comparison, the weapons that levelled Hiroshima and Nagasaki had yields of 15,000 and 21,000 tonnes respectively, which today would probably rate them as tactical weapons.

However, with practically all of the world’s nuclear treaties and restraints crumbling, it is now almost inevitable that one regime or another will experiment with the smaller nukes and seek to regularise their use, primarily as a means of terrorising their opponents. Only 74 of 197 nations have signed the Treaty to Prohibit Nuclear Weapons. None of the nuclear-armed states or their close allies have signed.

Informed commentators on the Israel-USA-Iran conflict consider the use of nukes, probably by Israel in the first instance, to be increasingly likely as the war goes against them and both Trump and Netanyahu fight to stay out of jail. Israeli Ministers have previously uttered threats to employ nuclear force, though they were later silenced by Netanyahu.

US official documents indicate the America has been preparing for a limited nuclear war for over seven years. Trump has refused to rule out use of nukes, and military observers suspect the US already has them in the West Asian theatre. He has also declared his intent to restart nuclear testing. Authoritative commentators are asking whether Trump is mentally ill – and the world’s most potent nuclear arsenal in the hands of a madman.

Compounding the danger is the frequent use of nuclear threats by Russian leader Vladimir Putin along with Russia’s recent warning that the West Asia conflict could go nuclear.

Observers also consider that the Israeli nuclear threat and its assassination of the chief Iranian opponent to nuclear weapons, Ayatollah Khamenei, makes it far more likely that the new Iranian regime will accelerate plans to build atomic bombs, in the hope of deterring an attack. So one outcome of the war will be a nuclear-armed Iran – the opposite of its professed intention. This will, in turn, spark new regional arms races, with at least seven countries, and probably more, seeking to acquire the civilisation-ending weaponry.

Thus, whether or not the Israel-USA-Iran conflict goes nuclear, it may still prove to be the pebble that starts the landslide to global nuclear holocaust.

A ‘small’ war

There is no such thing as a small nuclear war. Even a limited exchange of tactical weapons could kill 90 million people – far more than died in WWII – in the first few hours, according to modelling by Princeton University. The study refers to the European context, but its message has far wider application.

In the context of dozens of nuclear armed nations – many controlled by men of questionable sanity – the doctrine of Mutually Assured Destruction, which has kept the nuclear peace for 80 years, lapses into irrelevance. Little now prevents nations from committing suicide in their crazed desire to eliminate those they deem as foes.

Furthermore, any ‘small nuclear war’ can rapidly escalate into a far larger, global affair quite quickly and unpredictably. Unable to penetrate or understand their opponent’s motives, nations may choose to strike first and hardest, regardless of the ultimate cost to their own citizens. Indeed, this already appears a significant factor in the escalation of the West Asia conflict.

A current threat analysis made during the conflict finds that the threat of nuclear war to be higher than most periods of the Cold War, but not quite as high as its 1962 Cuban crisis and 1983 ‘Able Archer’ peaks, making it the third deadliest moment in human history since nukes were invented.

It is being stoked by the failure of arms control agreements, the increasingly pugnacious rhetoric of national leaders, and technical advances that could easily go wrong. Misinterpretation, miscalculation, political impulsiveness and an AI glitch have become primary triggers for an atomic war.

A nuclear explosion produces three instant killing mechanisms: a shockwave, a pulse of extreme heat, and a burst of deadly radiation. A very small 10kt weapon, detonated at ground level, causes severe shockwave damage up to 1km from the blast. The thermal pulse inflicts fatal burns and a firestorm up to 2kms. Flying debris kills or injures people several kms distant.

The radiation burst will kill unprotected people up to 1km away, and drifting fallout will create a potential death zone up to 10kms downwind. Larger weapons inflict proportionately greater death and destruction.

Those exposed to moderate doses of radiation develop acute radiation syndrome, which develops in stages: bone marrow is the first to fail, leading to uncontrolled infections and bleeding. Around half of those exposed to a moderate dose die within 60 days. At higher doses, the patient experiences severe vomiting, diarrhoea and internal haemorrhage. Death occurs within two agonising weeks, and no treatment can reverse it. At extreme doses, the heart and central nervous system collapse, and death occurs within three days. In a nuclear war, most radiation victims will receive little or no medical care.

Fallout from a nuclear strike contains particles with a half-life lasting from days to 30 years, so can go on killing for decades, without the need for new strikes. Gamma rays can travel long distances and penetrate most buildings unless they are sheathed in lead, thick concrete or rock. Long term effects include an epidemic of cancers, thyroid and immune system failure.

Globally, even a ‘small nuclear war’ could affect every country and every person, no matter how far away from the seat of the conflict, by means of the “nuclear winter”.

Figure 1. Freezing temperatures and darkness for years would destroy harvests worldwide following a nuclear exchange.

In a scientific paper published in 1983, Professor Brian Toon, Carl Sagan and colleagues calculated that the dust and smoke from a larger (5000 megaton) nuclear war would cut light to the Earth and reduce land temperatures to minus 15-25 degrees Celsius, destroying the entire world food harvest and causing universal starvation. It was this that persuaded Reagan and Gorbachev to pull back from the brink of catastrophe.

However, even a ‘small nuclear war’ of fifty or so tactical blasts would cover the Earth in a smoke cloud 30-100 kms deep within two weeks causing subzero temperatures for several years. The smoke would linger for years, possibly decades, ruining harvests everywhere. Between one and two billion people would die of starvation around the world. Everybody would go hungry. The world economy would collapse.

Iran’s deterrent

Three days before the US bombed the nuclear enrichment site at Fordow in 2025, a line of empty trucks was spotted by satellites at the facility. Intelligence assessment decided these were tasked to carry 408 kilos of highly enriched (60 per cent purity) uranium, part of a larger cache of 8.4 tonnes of uranium, to a place of greater safety.

If so, this leaves Iran with the capability to manufacture up to 14 atomic bombs or 300+ dirty bombs to deter a nuclear attack by Israel. It also has the ballistic and hypersonic missiles to deliver them, while Israel’s air defences are weakened. The radiation from a dirty bomb made from 60 per cent enriched uranium has a half-life of 740,000,000 years. While not deadly in the short term this could still render areas uninhabitable for the rest of history.

Whether this would deter a US or Israeli attack, given the unhinged state of their leadership and the moral cowardice of their governments, is not certain.

A wise course would be not to force Iran into such an escalation. But where is there wisdom in any of this?