Is it viable for the United States to impose a naval blockade against China in a potential conflict? That’s a critical question in the study of China’s maritime and energy strategies.

China’s crude oil dependence is obviously the key variable determining the success and failure of a blockade. Although China can produce many of its vital goods, such as grain and coal, in 2013 China imported 64.5% of its crude oil consumption. Oil-based liquid fuels, such as gasoline and diesel, are vital for vehicles. And an overwhelming proportion of China’s crude oil imports—with the exception of imports from Russia and Kazakhstan—rely on seaborne transportation.

But China’s reliance on seaborne oil imports isn’t matched by its naval capability. It doesn’t have overseas bases to support regular operations in distant regions. By contrast, the US Navy not only possesses formidable ocean-going capabilities, but also quantitative and technological advantages. That asymmetry between China’s high level of reliance on seaborne oil imports and its low level of naval capability to protect those imports means the US Navy could successfully interdict China’s seaborne oil trade.

Although China’s concern about a US blockade is often mentioned, few studies have attempted to provide a quantitative estimate of the consequence of a blockade. Using the inverse formula of energy intensity, drawing on statistics published by British Petroleum and the US Energy Information Administration, I produced a preliminary estimate that an energy blockade cutting off all 87% of oil imports that came by sea (that is, rather than overland or by river) would cause a direct reduction of 6.6% to the Chinese GDP (as measured by purchasing power parities), a figure equivalent to the size of the Australian economy. The indirect damage of a blockade in terms of reducing commercial/industrial efficiency would likely be even more serious. Therefore, I found a naval blockade could produce economic devastation and consequently a viable strategy for the US in a conflict with China.

Having concluded that the potential threat of oil blockade is serious, I then investigated the effectiveness of China’s counterstrategies to such hypothetical threat. I classify China’s counterstrategies to a US oil blockade into two categories: vulnerability-reduction strategies aiming at the protection of oil supply; and conflict-prevention strategies aiming at the avoidance of US blockade via the prevention of conflict with the US.

The two most discussed vulnerability-reduction strategies are the development of the PLA Navy to safeguard the seaborne oil imports and the construction of overland oil pipelines. But because of the large volume of China’s oil imports, and the distance between China and the oil producers in the Middle East, naval convoys would hardly be practical as a means for ensuring secure supply. A hundred-ship oil convoy, either during its 35-day trip, or during its fuelling and refueling, is an easy target for air/missile/submarine attack. Likewise, thousand-mile pipelines connecting China with Russia and Kazakhstan could be cut off by a single air strike. The protection of pipelines is virtually impossible. And complex oil refineries—difficult to rebuild—could also be targeted. Thus, I conclude that vulnerability-reduction approaches are costly and largely ineffective.

Nevertheless, it‘s more realistic for China to seek conflict-prevention strategies to counter a possible US blockade. There are many ways to prevent conflict with the US. For example, there can be ‘soft’ conflict-prevention strategies, such as diplomatic reassurance, and inter-military exchange programs. The key dilemma is that the pursuit of conflict prevention mustn’t hamper Beijing’s core security interests. In this sense, “hard” conflict-prevention approaches—especially more robust nuclear deterrence—might be an essential part of conflict prevention.

Because most contemporary US “war-winning” strategies, including Air-Sea Battle and naval blockade, aim at capitalizing on US conventional advantage, they downplay the “unwinnable” nuclear war. The US can conceptualize a conventional war with China because China, with a much smaller nuclear force can’t initiate nuclear exchange in a war with the US. China needs to transform its strategic nuclear force from one of minimal sole-purpose deterrence to a more robust multi-purpose deterrence. A robust Chinese nuclear deterrence could contribute to war prevention by replacing the option of “winnable conventional war” with “unwinnable nuclear war.” But, in order to construct a nuclear deterrence sufficiently robust to deter the US from engaging in a conflict with China, Beijing must make two major changes: it must renounce its No-First-Use declaration, and build up a strategic nuclear force more comparable to that of the US.

Xunchao Zhang is a student from the PRC who studies at the ANU. Earlier this year he was an intern at the Sea Power Centre-Australia. This article first appeared in ASPI’s Strategist here.

Image: U.S. Navy Flickr.