World war maybe 🕊️

In 431 BC, Athens and Sparta went to war. Sparta dominated the Greek world, but feared its reign would soon end. Athens was richer and increasingly powerful. Athenian historian Thucydides later claimed “the rise of Athens and the fear that this instilled in Sparta” made war inevitable.

That same dynamic may now be playing out between our world’s two most powerful nations, China and the United States. China, the upstart, is richer, stronger, and more assertive than ever before. The US is the incumbent, the world’s sole superpower, defending a global system it built and still dominates. Both are nuclear powers.

Thucydides Trap

It’s the Thucydides Trap. China’s president Xi Jinping has used the term for years, and namedropped Thucydides during Trump’s visit to China back in May. “Can China and the United States transcend the so-called Thucydides Trap and forge a new paradigm for major-power relations?”, the Chinese leader mused in a speech. 

The term was popularised by Harvard academic Graham Allison, who examined 16 historical cases in which a rising power challenged a dominant one. Twelve ended in war. Not great odds. Writing in 2012, Allison warned that “Thucydides’s trap has been sprung in the Pacific”. But causes of wars are rarely down to one event, person, or development. And some of the most significant transitions of power have been peaceful. After dubya dubya two, Britain stood down for the US. America and the Soviet Union avoided war for 40 years. Just. Germany and Japan bounced back post-1945, without reverting to their prior shenanigans. Is the Thucydides Trap more warning than prophecy?

1949-2027

At the nexus of US-China relations is an island in the Western Pacific. Taiwan sits about 100 miles off the Chinese coast, and has been governed separately since the Chinese civil war ended in 1949. Beijing considers it part of China and hasn’t ruled out taking it by force. Taiwan’s population increasingly identifies as Taiwanese rather than Chinese.

Washington doesn’t recognise Taiwan as an independent country, but it does supply weapons. It’s kept schtum on whether it would come to Taiwan’s aid in the event of attack. This policy of ambiguity worked while the military balance favoured Washington. It’s becoming harder to sustain now China has the world’s largest navy by number of vessels, thousands more missiles than the US, and a raft of new seafaring and amphibious kit.

One date comes up a lot: 2027. It’s the centenary of the People’s Liberation Army, and Xi has reportedly ordered the military to meet certain modernisation goals by then. Anniversaries matter to the Chinese Communist Party, but it’s not a given Xi will celebrate this one by starting a world war. Nonetheless, a stronger PLA gives Beijing more wiggle room.

God Bless America

America is still the most powerful military force the world has ever seen. It spent $1 trillion on defence in 2024, more than three times China, and more than the next nine nations combined. But wars are not decided by spending alone. For one, China would be fighting on its home turf. That carries a significant advantage, as any football team will tell you. The US would be operating across the vast expanse of the Pacific, leaning on aircraft carriers and submarines, and its bases in Japan, Guam, and the Philippines.

If Washington elected to stand aside, APAC allies might question the reliability of the US and its security guarantees. China would see fit to continue to project power in the Pacific, building its artificial islands, laying claim to international waters, and intimidating its neighbours. A capricious, America-first president might be exactly the thing China needs to make good on its promise of reunification.

Other means

Invading Taiwan would be one of the most difficult military operations in modern history. China would have to move large numbers of troops, vehicles, ammo, and fuel across a rough stretch of sea, land them on a small number of suitable beaches, and then fight through cities and mountains. The preparations would be hard to conceal from eyes in the sky and neighbouring US allies.

China could blockade Taiwan instead, interfere with shipping, seize islands, cut cables, disable satellites, or launch cyberattacks against banks and energy grids. Perhaps we’re already in a grey war with China as there’s strong evidence it has conducted many of these operations already, at least covertly. China could ‘quarantine’ the island, an act coercive enough to hurt Taiwan, but ambiguous enough to divide America and its allies over whether to act.

Cascade effect

In the event of invasion, China would need to establish control before American forces could rally. Retired US Lieutenant General Charles Hooper argues the opening phase of a Taiwan conflict would unfold in hours, not weeks. If the US decided to dither and delay, it could make intervention impossible.

The concern is a local war could very quickly pull in other nations. To push back against the Middle Kingdom, the US would be reliant on bases in Japan. China might decide those bases are legitimate targets, pulling Tokyo into the conflict. The Philippines would be in the crosshairs too. North Korea could use the distraction to put pressure on South Korea. Russia might test NATO’s resolve in Europe while American attention was elsewhere. It’s easy to see how things could get out of hand.

Mutually Assured Disruption

Taiwan is, of course, central to the semiconductor industry. TSMC (TSM) accounts for the majority of global chips and an even larger share at the cutting edge. Any disruption would hit smartphones, cars, data centres, medical equipment, industrial machinery, and weapons production. It’s estimated war over Taiwan could cost the global economy $10 trillion, roughly 10% of world output.

China would be badly exposed too. It imports much of its energy and food, and depends on maritime trade. A blockade of Taiwan could become a blockade of China, especially if the US restricted oil shipments through the Malacca Strait. Beijing knows this, which is one reason it has spent years reducing its vulnerability to American sanctions.

Called up

What about Britain? The UK is one of America’s closest partners, a member of Five Eyes, and part of the AUKUS security pact with the US and Australia. In a war with China, it could provide intel, cyber support, logistics, and naval assets. Even without British boots on the ground, we would be involved.

If the US fully pivoted to Asia, Europe would have to take more responsibility for deterring Russia, China’s close ally. Britain could face pressure to support Washington in Asia while strengthening NATO closer to home. It’s not obvious our armed forces are large enough, or that the defence industry is productive enough, to do much of either for very long.

Porcupine policy

The First World War began with the assassination of an unpopular Austrian duke. Before long, more than 30 nations across two alliances were at war, with around 20 million dead by the end of the conflict. It’s not hard to imagine something similar occurring over Taiwan. The big difference now is many of these countries have nukes.

Avoiding war ironically requires preparing for it. China is less likely to attack Taiwan if it believes the island can resist and America will intervene. Taiwan’s strategy of being the world’s chip factory is also a major plank of its defence strategy, its Silicon Shield. 

War games

A war between the US and China would be ruinous for both. It could destroy democratic Taiwan, push the global economy into depression and, most importantly, risk nuclear war. Even a limited, tactical nuclear skirmish could devastate the global climate and kill tens of millions through starvation, not least direct conflict. And that may be the best possible outcome. In most nuclear war gaming scenarios, total nuclear exchange is the inevitable conclusion. We’re talking about the end of the world, nothing less.

So, the costs are obvious, which is the best reason to think war can be avoided. The Chinese are serious people. Are they willing to risk it all over Taiwan? Is the West?