Published in Quadrant (Sydney), 29 April 2026
Thomas Hobbes published Leviathan in 1651, amid the wreckage of the English Civil War. We know him for his defence of the state: without a sovereign authority to impose order, human life reverts to a “war of every man against every man”, where existence is “solitary, poor, nasty, brutish, and short”. As great-power rivalry intensifies, we should ask how far that logic extends into the space between nations, where no sovereign authority exists.
Hobbes himself considered the question. He described sovereigns as living in “the state and posture of gladiators”, with forts, garrisons and spies on every frontier. Yet he thought interstate anarchy less ruinous than civil collapse, because organised states could preserve the industry of their subjects.
Two world wars showed he had underestimated how brutal this “gladiatorial” system could become. The second left Europe in ruins and convinced the survivors that armed coexistence was not enough. The comprehensive response to these catastrophes had no historical precedent: anchored by American power and expressed through the United Nations, the Bretton Woods institutions for monetary and development co-operation, the GATT and later the WTO, NATO and the web of treaties that grew around them.
Nobody submitted to a global Leviathan. But the post-war order was the closest thing to one: a set of rules, backed by American power, that tried to build something closer to the rule of law.
That order is now unravelling, fast enough to worry anyone who has benefited from it. It rested on a mutual bargain. The United States agreed to bind itself within a framework of rules and institutions. In return, it got allies in containing the Soviet Union and the privilege of issuing the world’s reserve currency. Smaller nations gained security, market access, and a voice in international institutions beyond their reach. The rules were imperfect, selectively enforced and occasionally violated by the very power that underwrote them. But they were rules, and for most states most of the time, they held.
Still, the arrangement had an inherent structural weakness that Hobbes would have spotted at once. A true Leviathan possesses a monopoly on force, and the post-1945 order had nothing of the sort. The five permanent members of the UN Security Council, the United States, the Soviet Union, China, France and Britain, could each veto enforcement against themselves. The Security Council could therefore punish only the weak, not the strong. The system worked only so long as the powerful chose restraint. Once they lost interest, it was exposed for what it had always been: a fragile convention, not a settled constitution.
Something similar happened after the Napoleonic Wars. In 1815, the major European powers agreed to manage their rivalries through diplomacy rather than war, in an arrangement known as the Concert of Europe. It helped prevent a general European war for much of the nineteenth century. Success rested on shared restraint, not enforcement; wars occurred, but they were contained.
The system required constant diplomatic care. When the powers began to treat the Concert’s restraints as optional rather than binding, it did not collapse overnight. It decayed, gradually and then suddenly. The powers that had maintained stability for a century sleepwalked, as the historian Christopher Clark put it, into the Great War of 1914.
The post-1945 order, like the Concert, depended on the major powers believing the system served their interests. When the Cold War ended, the United States lost its pressing reason to maintain the order. The 1991 Gulf War, in which a genuine international coalition reversed Iraq’s seizure of Kuwait without it resulting in a military quagmire, may have been the high-water mark. After that, enforcement faltered.
As Rwanda’s genocide unfolded, the world stood by. America and its allies occasionally broke their own rules, in Kosovo in 1999 and Iraq in 2003. But what corroded the order was not American rule-breaking. It was the refusal to act against those who openly broke the rules.
When Syria’s Assad used chemical weapons against his own people in 2013, Obama drew a red line, then stepped back from punitive strikes. Instead, he accepted a disarmament deal whose deterrent effect proved weak. Authoritarian rulers concluded that Western red lines could be blurred or bargained away. When Russia seized Crimea in 2014, the lesson was confirmed. The West imposed sanctions, but no direct military cost, and Putin drew the obvious conclusion. Each violation without consequence made the next more likely.
Yet the United States at least kept up the pretence that the post-war order mattered. American administrations might bend the rules, ignore inconvenient institutions or act alone, but they did not reject the system itself. They accepted it as legitimate even when they failed to uphold it.
But the pretence was wearing thin. Washington blocked appointments to the WTO Appellate Body from 2017, and by December 2019, it could no longer function. Even that could be read as frustration with an institution rather than rejection of rules.
While the trade system was being hollowed out, Russia shattered what remained of the security consensus when it launched a full-scale invasion of Ukraine in 2022. Ukraine is still supported by more than forty countries and billions in EU aid, but American commitment has wavered.
Until 2025, Trump could plausibly be called a symptom of the order’s decline rather than its cause. That distinction no longer holds. Under his second administration, the US has gone from inconsistent enforcer to active destroyer. Trump is both symptom and cause.
Since January 2025, Washington has threatened to annex Greenland, talked of retaking the Panama Canal, imposed tariffs on allies and adversaries alike, and openly admired authoritarian strongmen. Ukrainian President Volodymyr Zelenskyy says Washington has linked security guarantees to making territorial concessions to Russia. The US Secretary of State Marco Rubio denies this, but the claim’s credibility speaks for itself.
The US-Israeli strikes on Iran, launched without explicit congressional authorisation on contested legal grounds, took Trump’s logic further. European reactions were mixed; many governments preferred calls for de-escalation to legal condemnation. The pretence of a rules-based framework is dying less in argument than in diplomatic evasion. These signals travel far beyond Europe.
China is watching carefully because Taiwan is the next test. If Beijing concludes that the will to resist aggression has gone, that American security guarantees are unreliable, and that the costs of military action are manageable, the world, especially Taiwan, will feel it. Taiwan produces many of the world’s most advanced semiconductors. A war there would trigger another severe economic shock.
If Taiwan’s security cannot be guaranteed, every American ally must reconsider its own. States under the nuclear umbrella are reopening once-unthinkable questions. In South Korea, the debate is public, even as Seoul officially denies it. In Japan, the elite taboo is weakening, though official policy still rejects nuclear possession. Saudi Arabia has long signalled it would reconsider its stance if Iran went nuclear. Trade, security, and norms depend on one another, and all three are now fraying.
Why do American voters tolerate the dismantling of an order that has served them well? Hobbes saw that the willingness to accept rules, domestic or international, rests on recognising that order serves everyone better than chaos. When that recognition fades in one domain, it weakens in the others.
At the domestic level, the fading is already clear. Anne Applebaum’s Twilight of Democracy (2020) helps explain the mood: populations that once regarded liberal democracy as permanent have begun to find strongmen attractive.
The reason is partly generational: the order’s success corroded the fear that brought it about and sustained it. Eight decades without a great-power war made stability seem natural. The generation dismantling the order has no memory of the Hobbesian alternative.
But it is also material. Where liberal democracies have failed to deliver affordable housing, functioning public services, or rising living standards, voters see less to defend.
Without that generational memory, a president who ignores treaty obligations, threatens allied nations and turns the machinery of government against domestic opponents is hard to distinguish from the strongmen he admires. Robert Kagan warned in The Jungle Grows Back (2018) that the liberal order needed American power; he did not expect that power to turn against the order.
Voters who distrust their own parliaments and courts will not lose sleep over the WTO or the International Court of Justice. In the US, the same political movement is tearing down democratic norms at home and international norms abroad. The states most exposed are those that built their prosperity on the assumption that the order would hold.
European governments spent decades relying on American security while letting their own military capabilities wither. They treated NATO’s 2 per cent spending target as a wish, made themselves dependent on Russian energy, and neglected their own defence industries. Confronted with Russian aggression and American unreliability, Europe is responding belatedly and from a dangerously low base. Ammunition stocks are low, and capability gaps and procurement failures cannot be reversed in a single budget cycle.
Any Western democracy, including Australia and New Zealand, that outsources its security and assumes the order will hold, faces the same reckoning. Both built their post-war prosperity on American security and rules-based trade, and both assumptions are now in jeopardy.
Australia has begun to adjust. AUKUS, the security pact with the US and Britain, is a recognition, late but real, that the strategic environment has changed. New Zealand was slower to respond. Although Wellington is attempting a late catch-up with its 2025 Defence Capability Plan, its defence posture reflects decades of neglect. If Australia needs to prepare for a world without reliable American security, New Zealand needs to prepare faster.
What should countries like these do? They must diversify their trade and build coalitions with like-minded states. Groupings of France, Britain, Japan, India, Australia, South Korea and Canada offer the best available framework for sustaining the rules-based order.
Yet such groupings are probably not enough. Middle powers cannot enforce rules against great powers determined to break them, and no anchor state has volunteered. Part of the reason is that the old order made it harder than it needed to be.
The post-1945 order was not perfect. It conflated rules with Western liberalism, losing support from states that might have accepted shared rules while rejecting the philosophy. A future order needs to make a separation that the old one never did: rules-based, without being liberal. States that have no interest in Western-style democracy might still agree not to seize territory by force, not to weaponise or threaten trade and not to proliferate nuclear weapons. That distinction determines how wide the coalition can be.
For all its flaws, the post-1945 order helped underpin eight decades without great-power war, in which trade expanded, hundreds of millions escaped poverty, and small nations participated in international life. For countries like Australia and New Zealand, whose prosperity was built on an assumption that trade would be governed by rules rather than raw bargaining power, those decades were not merely pleasant but existential. But none of it was permanent. We are now discovering what comes after.
Most people remember Hobbes for “nasty, brutish, and short”. But his preceding words matter more: in the state of nature, there is “no place for industry, because the fruit thereof is uncertain … no arts; no letters; no society”. The state of nature is not just violent. It is poor, destroying the conditions for productive life before it destroys life itself. Investment stops, horizons shorten, innovation stalls. That is the world we are drifting back towards.
Unfortunately, the question for the nations that lived under the post-1945 order is no longer whether conflict between great powers is possible. It is whether anything remains to prevent it.
Hobbes wrote Leviathan because he had lived through the collapse of domestic order. What is collapsing now is order between nations, different in scale but not in logic. We have his warning and the lessons of two world wars. We are ignoring both.
The West is allowing it to happen, through negligence, complacency and the reckless actions of those who should know better. For small countries like New Zealand, the stakes are high, and the options are few.
That is not just nasty and brutish. It is short-sighted, too.
