The Cold War is over. Russia is a fading power. The most important geopolitical rivalry of the 21st century is between China and the USA. Any analysis of the conflict must take into account the possibility that it escalates into a hot war. This post explores how a direct conflict between the USA and China might unfold. It assumes strong AI has not been invented and nuclear weapons are not used.
The United States' interests have been basically unchanged since 1945. Its primary objective is to maintain the liberal world order (LWO), also known as the "rules-based international order". The LWO describes a set of global, rule-based structured relationships based on economic liberalism as embodied by the United Nations and the World Trade Organization. The LWO promotes political liberalism too, albeit much less consistently.
As the primary power behind the LWO, the United States designed it to maximize economic and political power of the United States. As the United States' relative power wanes, we may see a transition toward a more multipolar LWO.
China's interests have been basically unchanged since 1978. Its primary objective is to maintain internal domestic stability i.e. prevent regime change. There are two ways of keeping its population under control: via a police state and via economic development. The stronger it's police state the less economic development is necessary and vice versa. China's economic growth is slowing as its east cost gets closer to a Western standard of living.
The People's Republic of China did not get a seat at the table in 1945 when the LWO was designed. It wasn't even allowed into the United Nations until 1971. From 1945 until 1971, "China" was represented by the Republic of China i.e. Taiwan. This illustrates how the LWO favors American geopolitical interests and is one of the many reasons why the People's Republic of China seeks to annex Taiwan.
China has prospered under the LWO. Rather than establishing broad international coalitions, China tends to pursue its interests bilaterally. With a few exceptions (like the dispute over the South China Sea) China is content to play according to the rules of the LWO.
Besides annexing Taiwan, China's geopolitical interests mostly revolve around securing markets and raw materials to fuel its economic development. This is the motivation behind 一带一路 (the Belt and Road Initiative).
The United States dominates global military spending.
Military spending is a trailing indicator. What really matters is the size of each nation's respective economy. Metaculus predicts a 1.7 China-to-USA GDP ratio in 2050. The PPP difference will be even higher.
This underestimates the relative strength of the USA because the USA has many close allies: The European Union, Britain, Japan, South Korea, Taiwan and so on.
China has North Korea.
The advantage to America is it has allies to call upon. The disadvantage to America is it has allies it must coordinate with and defend. America is spread thin. China focuses its attention on its smaller sphere of influence.
Of all the potential points of conflict, the obvious ones are Taiwan and the South China Sea. For the purpose of this analysis, suppose Taiwan declares independence from China in 2050 which causes China to attack Taiwan which causes the United States to attack China.
The last time something like this happened was in 1949 when the Kuomintang fled to Taiwan. The United States refused to get involved until the Korean War in 1950. The United States sent its Seventh Fleet into the Taiwan Straight. American naval supremacy kept the People's Republic of China from advancing into Taiwan, thus establishing the status quo which remains until today.
The United States maintains naval dominance over China. This will not last. China's PPP surpassed the United States years ago. China's GDP will surpass the United States well before 2050. Most importantly, the crown jewels of the United States' fleet will be almost useless in a direct conflict against China.
Ships vs Guided Missiles
When the United States wants to project power to a faraway land it uses aircraft carriers. In the 1996 Taiwan Strait Crisis, the United States sent two aircraft carrier battle groups into the Taiwan Strait to demonstrate solidarity with Taiwan.
Aircraft carriers dominated the seas in the second half of the 20th century because planes used to have short ranges and missiles used to be dumb. Today, airplanes have long ranges and missiles are smart.
A Chinese DF-21D anti-ship ballistic missile is believed to have a range in excess of 1,500 km. The newer CH-AS-X-13 has a range of 3,000 km. It can be launched from an airplane so its effective range is even farther. I estimate anti-ship missiles cost about $2 million each. An aircraft carrier costs more than $10 billion. Hiding an aircraft carrier battle group on the open sea isn't possible. The only way aircraft carriers could be remotely viable in a hot war between the United States and China would be if they had very reliable missile defense systems.
Israel's Iron Dome blocked 90% to 95% of incoming missiles in this year's Israel-Palestine crisis. That means it missed 5% to 10% of incoming missiles. A Hamas Qassam rocket is primitive. It is propelled by a mixture of sugar and potassium nitrate (ordinary fertilizer). It is not even accurate enough to use against military targets. A Qassam rocket is to a Chinese CH-AS-X-13 what a Mitsubishi A6M Zero is to an F-16.
I predict at least 5% of guided missiles can penetrate a surface fleet's missile defense system in 2050. If my numbers are right then either side can sink a $10 billion aircraft carrier with no more than $40 million in guided missiles.
An Arleigh Burke-class destroyer costs $2 billion per ship. Surface ships are basically going to be obsolete in a direct war between superpowers. The battles of the sea will be fought with aircraft, missiles, drones and maybe submarines.
I expect China will not be able to establish air supremacy far beyond its borders and that the United States will not be able to establish air supremacy over mainland China. Without air supremacy, neither side can protect aircraft carriers and transport fleets. This makes amphibious invasions difficult. Except Taiwan isn't far beyond China's borders.
Taiwan's military can be quickly destroyed by a Chinese attack. Taiwan itself is too weak to repulse China on the beaches. If Taiwan wants to maintain its independence then it needs dug-in defenders. Taiwan's mountainous terrain is advantageous here. Taiwan already conscripts all qualified males. It should be training them in guerrilla warfare. This is not happening. Taiwan should also have weapons caches and underground bunkers strewn all over the island. It doesn't.
How many troops would it take to conquer Taiwan?
- A Chinese invasion of Taiwan might be similar to a United States invasion of the Japanese homeland in 1945. In 1945, the United States' Project Downfall projected an invasion force of 5 million was required to subdue a population of 70 million. Projecting from this, an invasion force of 2 million might to be necessary to subdue Taiwan's population of 23 million.
- On the other hand, armies today are more efficient than they were in 1945. (People are more docile too.) Afghanistan has a population of 40 million but US troop levels in Afghanistan reached a height of only 100 thousand. It might take China only 50 thousand troops to subdue Taiwan.
I'm not sure which number to use. 2021 Taiwan is a lot like 2021 Japan but 2021 Japan is very unlike 1945 Japan. Taiwan is also unlike Afghanistan. It might take even fewer than 50 thousand troops to subdue Taiwan.
If 50 thousand troops is all it takes then China could land them quickly before the USA gets its act together. But if 2 million is what it takes to conquer Taiwan then China would need a bigger army than it has right now. Also, you can't land an invasion force of 2 million troops overnight. China would have to win the initial missile exchange and then maintain air superiority while it landed troops in Taiwan.
Things get hard to predict from here. What happens depends on the decisions of individual world leaders and the determination of various peoples.
In Darknet Diaries Episode 21: Black Duck Eggs, Ira Winkler tells the story of how his team broke into a major datacenter containing billions of dollars worth of technology.
Well, the first time you steal a billion dollars it’s a bit of a rush. After you’ve done this so many times it’s almost expected. Frankly, it was really unclimactic to actually take over control of all their computers in the RND center.
I know, right? Who cares if you can just walk into a datacenter and steal a billion dollars worth of advanced technology? It doesn't mean anything when you have a get out of jail free card because you are doing an officially-sanctioned penetration test. Except that after the penetration test Ira Winkler's team discovered a physical "Chinese intelligence operation in the middle of this small town, directly across the street from the research and development center of a Global 5 company".
For every hack we hear about there are many hacks we don't hear about. When you break into an adversary's computer network the first thing you want to do is establish persistence. Most of those hacks we don't hear about probably establish persistence. I would be surprised if China and the United States hadn't established persistence in most of each others' critical systems.
In the event of a hot war between the United States and China, both sides will burn most of their zero-days immediately to cause as much disruption to the enemy as possible. It takes a lot of work to clean a hacker out of one of your systems. The cyber onslaught will probably overwhelm both sides' ability to reset their software. They will have to focus on the most critical systems of all: communications.
I expect all but the most secure systems (think "US president's personal phone") will be entirely compromised. However, there are many ways to communicate. Both sides can improvise. Since secondary channels abound, it might be better just to spy on enemy communications instead of breaking them.
It is theoretically possible to take control of enemy weapon systems too but I don't think this will have a major impact. Weapon systems will continue to have human beings in the loop. Human beings can't be hacked the way computers can.
I think compromised weapons systems will just be taken out of commission rather than commandeered. Some of them might be destroyed, but I think most will just be rendered temporarily inoperable.
Satellites serve four purposes: reconnaissance, communication, navigation (GPS) and destroying other satellites. GPS going down would inconvenience both sides but it wouldn't be decisive. There are other ways of navigating. The same goes for satellite communication.
The most important use of satellites is reconnaissance. Aerial drones are nice but they can't see as much at once as a camera in outer space. If both sides are restrained in their use of nuclear weapons then they might also be restrained in space warfare. That seems overly-optimistic to me. The primary objective of both sides will be to preserve their spy satellite capability while destroying the enemy's.
The price of space travel is going down. We can expect a large increase in the number of satellites between now and 2050, including spy satellites and anti-satellite satellites. It is plausible that satellite warfare could trigger Kessler syndrome in low earth orbit where collisions cascade into a giant mess of debris.
Protracted Total War is Unlikely
The initial exchange of missiles and zero-days will be fast. Critical tactical decisions may occur in the first few hours. The decisive fighting could be over in a matter of days. The limiting factor isn't technical. It's the speed at which leaders can make decisions.
After a few weeks, both armies will be running out of missiles. Both civilian populations will have suffered massive damage from cyberattacks on their civilian infrastructure. If satellite warfare triggers Kessler syndrome then much of the world's communication infrastructure could be irreversibly damaged. The global economy would be a mess. Economic chaos would be bad for US interests and even worse for Chinese interests.
If we do see a protracted war then it matters a lot what countries get involved. A conflict where India or Russia joins the fray is very different from a conflict where they don't. Whatever happens, the tech level will probably go down. Advanced weapon systems like stealth drones take a long time to build. Destroy a few major semiconductor fabricators and the whole world runs low.
But it's hard for me to imagine a protracted war on the scale of World War II. In the past, getting your cities bombed was a small price to pay in order to expand your territory. China may sieze some already disputed territory like Taiwan or Kashmir. But it doesn't want to administer a large empire. China's primary objective is to maintain domestic stability. Annexing Afghanistan or Vietnam or Pakistan would make China harder to govern, not easier.
China's secondary objective is to secure access to resources and markets. Destroying the United States might help tear down the LWO, but if China dragged itself down alongside the United States then that would just open up a power vacuum for countries like Brazil, India and South Africa.
The United States isn't an expansionary power either. America likes the LWO because the LWO supports American interests. I don't see America sacrificing its own hegemony to preserve the LWO.
The Seven Years War happened because Britain and France were expansionary powers. World War One happened because the European powers were expansionary. World War Two happened because Germany, Italy and Japan were expansionary powers. The United States and China aren't expansionary powers.
Instead of a protracted total war, we'll probably see a ceasefire or deescalation. Besides control over Taiwan, the most important thing to come out of a conflict like this is a (re)establishment of the world order. A war would clarify who is and isn't a superpower (anymore).
If things go longer then it would be because the United States' military force is spread around the world. Its reserve forces could take weeks just to get to China. ↩︎