US Weapons Sales to Taiwan: Upholding the Porcupine Strategy

The recent announcement that the US will deliver Taiwan $3.4 billion of equipment in new arms sales elicited predictable consternation from Beijing. While much of the public focus has been on the size of the arms package, an arguably more significant facet has been ignored: its composition. Yet it is this, and the lessons it conveys about the ways that states can support smaller partners, which is perhaps the most important aspect of the arms sale.

The most common interpretation of the arms deal is that a sale of this size is symptomatic of the deepening rivalry between the US and China. Viewed in historical context, however, the arms sale is not as substantial as it might seem at first glance. In 2010, for example, the US approved a $6.4-billion arms sale to Taiwan which included assets such as PAC-3 surface- to-air missiles and upgrades to Taiwan’s F-16 fighter fleet. Prior to this, the George W Bush administration offered to sell Taiwan roughly $18 billion of equipment in 2001, including diesel electric submarines.

What’s New?

What is most noteworthy about the deal is not the size of the package but the way in which the composition of systems differs from previous arms transactions between the US and Taiwan. Those focused on relatively limited numbers of expensive platforms such as the F-16 and the Patriot system. The assumption underpinning this in US planning was that the Taiwanese armed forces could realistically contest the dominance of the People’s Liberation Army (PLA) in the skies and seas near Taiwan, at least for a time, until US intervention materialised. The rapid modernisation of the PLA has largely put paid to this aspiration.

The present arms transfer reflects a shift to what might be dubbed a ‘porcupine strategy’ – fortifying a weak state to render the risks and costs of invasion unacceptable to a large power. This approach, which does not emphasise striving for air or sea control, but instead making power projection unacceptably risky for the other side, can be delivered by a range of cheap asymmetrical assets. 

For example, the 100 truck-mounted Harpoon anti-ship missile launchers being delivered to Taiwan could significantly attrit China’s still limited fleet of amphibious vessels – particularly as they close in to deliver armoured forces ashore with surface connectors. The fact that there are a limited number of areas on Taiwan where a landing can be conducted means that defenders can anticipate the likely locations of Chinese amphibious craft and can concentrate surveillance assets such as UAVs near these areas to identify targets.

Other components of the package, such as mines and UAVs, similarly reflect a shift in emphasis from challenging the PLA for control of the Taiwan straits and the skies above them towards cost imposition from a recognised position of weakness. The third major component of the sale, the HIMARS multiple rocket launcher system, could play a variety of roles from disrupting PLA forces that land on Taiwan’s beaches to conducting longer-range strikes against forces marshalling on the mainland using missiles such as Raytheon’s DeepStrike. What all these systems share in common is that they are individually cheap and can thus be bought in large numbers for the cost of a single exquisite platform. These systems can be readily dispersed and camouflaged and can pose a threat to Chinese assets that are disproportionately expensive.

Small is Beautiful

This reflects a broader shift in the character of war, which increasingly favours small states. Indeed, domestic variants of many of the systems being sold already exist in Taiwan, for example the Hsiun Feng cruise missile series and the RT-2000 multiple launch rocket system. Along with the aforementioned assets, even cheaper systems such as loitering munitions,  ‘smart’ naval mines and swarms of cheap anti-vehicle and anti-personnel UAVs will be deployed on future battlefields. The number of such platforms available to even weak actors will likely increase in the future as the diffusion of advances in automated assembly and additive manufacturing makes it possible to rapidly produce such systems in bulk.

This raises important strategic questions for major powers attempting to support smaller allies against territorial revisionism. First, the changes identified may enable greater responsibility for self-defence to be shifted to the allies themselves. Granted, Taiwan’s island geography makes it uniquely defendable, but the changes described above are not limited to the maritime domain. The proliferation of large numbers of cheap self-targeting munitions, along with the ISR to vector them in, will likely make power projection difficult on land as well, with ramifications for regions such as the Baltics. In certain cases, smaller partners may benefit from the transfer of either the requisite armaments or support with regard to building their own production facilities, but they will require less direct military support to deter invasion by larger neighbours. Burden-shifting to smaller partners, then, may enable great powers to support them without taking the escalatory risks of directly confronting a major power rival.

However, it is in scenarios short of outright invasion where smaller partners may still require direct military assistance. To use the example of Taiwan, its robust approach to preserving its defence capabilities may well thwart an amphibious invasion, but would do less to prevent other forms of coercion, such as a potential future Chinese air and naval blockade which threatened Taiwan’s energy supply. While the threat of blockades may not cause Taiwan to cede its independence, it could force future Taiwanese leaders to adopt a more accommodating approach towards China. As such, abetting Taiwan in building and hardening its emergency stockpiles of critical resources and rebuilding currently atrophied US naval capabilities for running convoys under contested conditions might be the most fruitful way the US military can contribute directly to Taiwan’s security. This may also be true with regard to other allies, which may become increasingly difficult targets for a direct, full-scale invasion but may require help maintaining lines of supply and national resilience capabilities against less escalatory forms of coercion, from cyber attacks to blockades and limited kinetic raids.

The views expressed in this Commentary are the author's, and do not represent those of RUSI or any other institution.