Is the US Stronger than China?

On the dangers of the GDP fetish

On the pages of Foreign Affairs, Brooks and Wohlforth recently argued that the world is still unipolar. Is that true?

In a famous article published in 1999, Wohlforth had argued that, contra expectations of a fleeting “unipolar moment” (Krauthammer 1990), American geopolitical supremacy was likely to persist for decades. Wohlforth’s prediction of unipolar stability was prescient. He argued that the international system was unambiguously unipolar because (1) the US had a very large margin of superiority over other powers; and (2) the US was preponderant across domains relevant to the balance of power.

The United States enjoys a much larger margin of superiority over the next most powerful state or, indeed, all other great powers combined than any leading state in the last two centuries. Moreover, the United States is the first leading state in modern international history with decisive preponderance in all the underlying components of power: economic, military, technological, and geopolitical.

William C. Wohlforth. “The Stability of a Unipolar World,” International Security, Vol. 24, No. 1 (Summer 1999), pp. 5–41. Emphasis in the original.

In other words, there was only one great power in the system because the military, economic, and technological gap between the US on the one hand and Japan, China, Germany, and Russia on the other was so large that none of these lesser great powers had much hope of closing it for a long time.

In what follows, I will show that Wohlforth was correct in 1999 but wrong in 2023. Gilpin’s law of uneven growth has transformed the polarity of the international system. The world is no longer unipolar. Specifically, due above all to extremely rapid industrialization, China is now unambiguously a great power; the US margin of superiority over China is ambiguous at the very least; only the military gap remains somewhat large, and that too is closing really rapidly.

There is some disagreement among scholars on whether GDP at market exchange rates or purchasing power parity has a stronger signal of underlying strength. Taking the latter first, according to statistics compiled by the Maddison Project, Chinese GDP at purchasing power parity was 44% of the US’s in 1999. Already by 2018, it was 100% of US GDP.

Wohlforth may quibble that GDP at market rates is more relevant to the war-making abilities of modern states because, say, the cost of weapons is reckoned at market rates; not purchasing power. This is not so compelling because, among other reasons, most weapons production in both the US and China is domestic. The relevant capacity is the fiscal capacity of the two great powers to afford weapons systems. And the actual cost of weapons depends on aggregate productivity in the defense-industrial base.

Regardless, even if one accepts GDP at market rates as the ground truth, the picture is no longer rosy. China’s GDP (including Hong Kong and Macao) at market rates has grown from 13% of US’s in 1999 to 72% by 2022. Wohlforth’s unambiguous superiority is no longer unambiguous by this metric.

The idea that the economic size and industrial development of the powers was the decisive conditioner of war-making capabilities emerged from World War I. The dominance of firepower over mobility meant that wars would be wars of attrition fought along long, static fronts where prodigious quantities of munitions would be expended until one side capitulated. Unlike agrarian societies of similar demographic size, big industrial countries could field armies of several million men; armies that were voracious consumers of munitions, industrially manufactured war material, food and other supplies. Such massive armies could therefore be fielded for any appreciable length of time only by countries of great economic size and industrial strength.

Essentially, wars of attrition tested the capacity of the great powers to sustain the war effort for longer than their adversaries. In a series of monographs and edited volumes, Mark Harrison argued that this capacity was best proxied by the share of GDP not required for feeding the populace. Harrison argued that the insurgents in the midcentury struggle stood no chance because the Allies enjoyed crushing material superiority.

Yet, there were problems with Harrison’s social scientific theory of war outcomes. Simply put, America’s defense-industrial superiority did not cause the defeat of Germany because the bulk of lend-lease went to Britain and the US directly went into combat against the main German divisions only in June 1944—well after a strategic decision had been reached in the Soviet-German war. The midcentury struggle was, in fact, almost exclusively decided on the Eastern Front—it was the Red Army that defeated the Wehrmacht.

And on the Eastern Front the social scientific theory of war is unpersuasive, for the mobilized GDP ratios favored the Germans during the decisive phase of the Soviet-German war, 1941-1943. Harrison’s own data show that, as late as 1943, the ratio of Soviet to German mobilized GDP was 1.1, as was the ratio of raw GDP.

So, how did the Reds do it? Simple: the Soviets simply produced more weapons than the Germans. Even though the ratio of mobilized GDP was 1.1 in favor of the Germans, the ratio of weapons production was 1.5 in favor of the Soviets! (Both of these tables are from my “Western Perceptions of Soviet Strength in the Soviet-German War,” which was based on archival work in the O.S.S. archives under Adam Tooze’s supervision.)

The problem with the GDP fetish is that what really matters in protracted great power wars of attrition is not economic size per se, but defense-industrial production capacity. GDP serves as a good proxy only in as much as it captures variation in the latter. The position of your analyst is that, instead of using proxies like GDP, we need to directly interrogate the defense-industrial base. What does that say about the present balance of underlying war-making capabilities?

As Richard Baldwin has shown, the global production system is strongly characterized by regional cross-border value chains. There are three poles that serve as the hubs in hub-spoke networks: the US, Germany and China. US industrial base is spread out over North America; Germany’s is spread out over Europe; and China’s is spread out over Asia. So, China is unambiguously a pole of global production in a network sense. But how much value is traceable to China itself?

This is where Wohlforth et al. need to pay real attention. At 30% of global manufacturing value-added, China is as large an industrial power as America and Europe combined. If the relevant causal diagram (‘industrial strength → defense-industrial power → military strength → war outcomes’) is correct, then the world is indeed unipolar—with China as the unipole!

We’ll leave the detailed examination of the defense-industrial base to a future dispatch. For now, we can review some proxies of the scale of industrial capacity. Electricity generation is a useful proxy of industrial scale. China surpassed the US around 2010. It now produces twice as much electricity as the United States.

In Ukraine, we’ve seen how sustaining production of basic materials can be challenging. Specifically, there’s been a running crisis over the production of artillery shells. Even though every war since World War I has been, first and foremost, an artillery war, the tendency of Congress and the Services is to focus on sexy and expensive weapons systems to the neglect of basic capabilities. Now, the underlying capacity that is relevant to all such capabilities is the scale of casting production. China’s casting production in 2020 was five times as large as that of the United States’s. I’m greatly worried that the United States has let its defense-industrial base deteriorate while China’s has been growing in leaps and bounds.

Matthew Kroenig argued on the pages of National Review that the US has the capacity to fight and contain both Russia and China simultaneously. Unfortunately, he is wrong. The United States is not in absolute decline; it is in relative decline because of Gilpin’s law of uneven growth. China has grown so powerful that Asia will absorb the US’s entire war-capabilities if the US is to hold the line in Asia at all. In particular, China is rapidly closing the gap in strategic arms. In a tripolar nuclear order, the US will simply not be able to rely on threats to escalate to deter forcible revisions of the territorial status quo. As I’ve argued previously, the US will be forced to encourage Europe to field it’s own deterrent and permanently depart Europe for Asia. This is the price we must pay for the Schmittian clarity being pursued by US elites.

The United States does enjoy military primacy. But even the military gap is rapidly closing. We’ve entered what Krepinevich calls a ‘mature precision-strike regime.’ Russia, China, and to a lesser extent, others, have acquired formidable reconnaissance-strike capabilities of the sort that the US had a monopoly on in 1999. In a war between two such powers, the most important question is the survivability of strike platforms. The US military is planning to disperse and harden its bases in the Western Pacific. It will also have to rely on more survivable strike platforms like quiet nuclear-powered attack submarines and long-range bombers. Fortunately, the insular geography of Taiwan is highly advantageous for the defender because of what Mearsheimer called ‘the stopping power of water.’ So, even after the balance of locally-available forces becomes challenging and the strategic gap closes, the US will be able to hold the line in Taiwan.

The United States still enjoys what Posen called ‘command of the global commons.’ That too has eroded considerably, however. US warplanes cannot approach the territory protected by the air-defense forces of the other great powers. The US monopoly on global power projection does remain intact. No other power has the strategic airlift and sealift capabilities to project power everywhere on the globe. And behind two oceans, the US enjoys tremendous security that no Eurasian power will ever be able to afford. But geography cuts both ways. Because the other great powers are all located in Eurasia, they can rely on interior lines of communication to supply any war effort on their peripheries, while US ships and planes have to cross thousands of miles of open ocean to reach forward bases.

The US military knows how to run harder than others. I am not so worried about that. The US faces something like even odds that the military gap will remain its favor a decade or even two out—at least if the US can manage to focus exclusively on Asia. The problem is the strategic autism of Jake’s foreign policy. The principal goal of US policy must be to make it across the power transition in one piece. Great power war in the twenty-first century must be evaded. That will require both deterrence and reassurance. Our present policy course—above all, the chips escalation—is convincing the Chinese that they must fight us to secure their place in the pecking order of nations. This is dangerous and poses unacceptable risks. And we’re running out of time to right the ship of state. As I’ve written before:

Instead of trying to pull the other guy down, we should try to run harder ourselves. And we must find more deliberate and less escalatory ways to persuade the Chinese to moderate their behaviour in domains where we find it unacceptable.

Policy Tensor, The Strategic Implications of a Tripolar Nuclear Order. March 2023.