Antinuclear

But I think she goes too far when claiming Islamic State is the most significant threat to the global rules-based order to emerge in the past 70 years, including the rise of communism and the Cold War.

The Cold War was not a period of comforting stability and mutual understanding of avoiding ­Armageddon. To the contrary, it was a time of deep strategic uncertainty and extraordinary danger. There were numerous near misses from the Cuban missile crisis in 1962 to the events of 1983, when the Soviet leadership believed the US was about to embark on a disarming first nuclear strike.

When US president Ronald Reagan saw the film The Day After it had an enormous impact on him. Pentagon briefings advised him that an all-out nuclear exchange between the Soviet Union and the US would see about 100 million cas­ualties on both sides in the first 24 hours and that America, the Soviet Union, most of Europe and Japan would cease to exist as modern functioning societies.

Much of the rest of the world, if not all of it, would have been ­subject to a nuclear winter ­involving massive radiation and catastrophic climate change.

Civilisation as we knew it would have ceased to exist.

If that wasn’t an existential threat to international order and the system of nation-states, let alone the survival of the human race, I don’t know what is.

Of course, if a terrorist organisation gets hold of a nuclear weapon and explodes it in a major Western city, such as New York, there would have to be a response in kind. And it is precisely here where Islamic State is so vulnerable to massive retaliation. Unlike other terrorist bodies, such as al-Qa’ida, Islamic State aims to establish a so-called caliphate — involving the acquisition of territory, towns and infrastructure. That will make it highly vulnerable to massive military strikes and utter destruction.

In the meantime, it is not as if Islamic State is getting a free hand in the Middle East. ………….

Two prominent American strategic experts, Graham Allison and Dimitri Simes, have published a persuasive article in the current edition of The National Interest arguing Russia and the US are stumbling to war.

They observe that disagreements over the international system and the prerogatives of major powers in their immediate neighbourhoods are the most dangerous disputes of the sort that have historically produced the greatest conflicts and challenges to the international order.

Canberra should not become so obsessed with the threat from ­terrorism, as real as that is, that we underestimate these other ­palpable threats to world order.

Paul Dibb is emeritus professor of strategic studies at the Australian National University.