Post-INF Indo-Pacific: The strategic potential of US-Philippines cooperation
Post-INF
Indo-Pacific: The strategic potential of US-Philippines Cooperation
WRITTEN BY RUPERT SCHULENBURG
18 May 2023
China’s decades-long military modernisation has shifted the power balance in the Indo-Pacific, eroding US military primacy. China currently has an inventory of over 2,000 ballistic and cruise missiles, as well as the world’s largest navy, which has a total of 340 ships and submarines. These capabilities pose a significant threat to the US bases and surface ships around China’s periphery, undermining the United States’ ability to defend Taiwan and its formal allies.
Therefore, there has been growing concern in Washington that China could soon be confident enough to invade Taiwan — even as soon as 2027. While warnings of a near-imminent invasion are perhaps overblown, the considerable improvement of China’s military capabilities has prompted calls and action towards implementing a more lethal and dispersed US force posture in the Indo-Pacific.
Given the growing concern of a looming Taiwan contingency, US-Philippines defence cooperation could make a significant contribution to regional deterrence. Were the US to field a ground-based anti-ship missile system, and Manila agreed to host this weapon system on a rotating basis, this would allow the US to hold China’s navy under greater deterrence, while also remaining outside the worst of China’s conventional missile strike volume.
This combination of lethality and survivability could undermine China’s ability to invade Taiwan, bolstering deterrence. Moreover, US anti-ship missiles would be unable to target China’s land-based nuclear forces. This could make China more restrained in its potential punishment of the Philippines and make Manila more open to hosting US anti-ship missiles.
Strategic opportunities and risks
In 2019, the US retook the ability to field intermediate-range precision-strike missiles. That year, the Trump administration withdrew from the Intermediate-Range Nuclear Forces (INF) Treaty, which banned the US and Russia from fielding ground-based missiles with ranges between 500 and 5,500km. Just a day after withdrawing from the Treaty, the then Secretary of Defense, Mark Esper, stated that the administration was looking to deploy missiles within “INF range” in Asia. However, following Esper’s remark, regional US allies declared that they did not currently have plans to host such missiles. This hesitation can be explained by concerns over how China would respond if they agreed to host US missiles.
A rotational deployment of US ground-based anti-ship missiles to Philippine bases would constitute a major deepening of US-Philippines defence cooperation and could bolster regional deterrence.
China’s prior treatment of South Korea illustrates where this worry stems from. In March 2017, the US and South Korea began to deploy their Terminal High Altitude Area Defense (THAAD) anti-missile system, intended to intercept North Korean missiles. Beijing strongly opposed this deployment, claiming that the THAAD system’s radar would allow it to detect launches from China’s land-based nuclear forces and discern real warheads from decoys, undermining its nuclear deterrent. Beijing consequently retaliated with an economic boycott that cost South Korea’s economy USD 7.5 billion in 2017.
One reason why China was so sensitive to the THAAD deployment was that its nuclear arsenal is particularly vulnerable, due to being comparatively small (albeit growing) and intermingled with conventional weapons. As such, China would likely be highly sensitive to deployments of ground-based missiles that could reach its mainland.
US missile strikes, even if aimed solely at degrading China’s conventional ballistic missiles, would simultaneously threaten its nuclear arsenal. This runs the risk of nuclear escalation, as US strikes could lead to a ‘use-or-lose’ dilemma, whereby China — in order to make the US back down — would potentially be incentivised to ‘go nuclear’ before it no longer can. In view of this, US allies are likely to be averse to hosting US missiles that have a land-attack capability.
Considering those risks and concerns, the US should instead pursue ground-based anti-ship missile deployments in the Indo-Pacific. These would be less threatening to China, as they would not target the mainland and its land-based nuclear forces. For this reason, one can expect US allies to be more open to hosting anti-ship missiles, as China would be more restrained in how it may punish these missile-hosting nations. Moreover, anti-ship missiles would pose less severe escalation risks, which could dampen allies’ concerns over an inadvertent nuclear escalation in a crisis.
Basing US anti-ship missiles in the Philippines
In 2014, the US and the Philippines signed the Enhanced Defense Cooperation Agreement (EDCA), which allows the US to rotate its forces through Philippine bases for extended stays and to build and operate facilities on these bases. The US is also approaching the ability to field a ground-based anti-ship missile system. In December 2022, the US Army received a prototype of the Typhon Weapon System (TWS), a trailer-mounted launcher that can fire a Tomahawk cruise missile. An anti-ship variant of the Tomahawk exists: the Block Va, which can strike moving naval targets as far as 1,600 km.
The Philippines would be a highly effective location for a battery of TWSs, armed with Block Va Tomahawks. If based at Cesar Basa Air Base on the Philippines’ northern island of Luzon and at Antonio Bautista Air Base on the western island of Palawan, the Taiwan Strait would fall within range. Moreover, these two bases fall outside the worst of China’s conventional missile strike volume, making them less vulnerable than bases in Japan or South Korea.
According to recent RAND Corporation calculations, China has approximately four short-range ballistic missile rounds and 2.4 medium-range ballistic missile rounds per launcher. These types of missiles form the majority of China’s conventional missile force. In this way, US bases on Okinawa are within range of approximately 250 of China’s short- and medium-range ballistic and cruise missile launchers.
In contrast, Cesar Basa Air Base and Bautista Air Base are within range of approximately only 125 and 40 launchers, respectively. As such, missile batteries based in the Philippines would face a weaker strike volume, making them more survivable than if they were located in East Asia. While China could supplement its short- and medium-range missile volume with its intermediate-range missiles (DF-26), they would likely be reserved for farther targets such as US bases on Guam.
Ground-based anti-ship missile batteries that are rotationally deployed to bases in the Philippines could improve the US’ ability to threaten China’s major surface combatants and amphibious assault ships. As such, the presence of this capability could bolster Washington’s ability to deter a hypothetical Chinese invasion of Taiwan. The potential of the US to make full use of this capability would, however, be hindered by the fact that the EDCA does not permit permanent bases. This means that this proposed arrangement would, at least for now, have to be on a rotational basis for extended stays.
Foundations for cooperation
The Philippines’ strategic interest in Taiwan’s security and reinvigorated interest in security cooperation with the US could result in openness to such a missile-hosting proposal. At their 2+2 Ministerial Dialogue in April, as well as a leadership meeting in May, the US and the Philippines “reiterated” and “reaffirm[ed]” the “importance of maintaining peace and stability across the Taiwan Strait”.
President Ferdinand Marcos Jr., who took office last year, has not explicitly stated that the Philippines would assist the US in a Taiwan contingency, like other US allies. However, he acknowledged in an interview in February this year that “when we look at the situation in the area [...] it’s very hard to imagine a scenario where the Philippines will not somehow get involved”.
Manila has good reason to help the US defend Taiwan’s security. In addition to Manila’s recently declared concern for the “safety and well-being of the more than 150,000 Filipinos living and working on the island”, Taiwan under China’s control could be militarised to impede US naval and air operations in the Philippine Sea, undermining the Philippines’ security.
Under President Ferdinand Marcos Jr., Manila has demonstrated renewed enthusiasm for security cooperation with Washington, departing from former President Rodrigo Duterte’s pursuit of closer relations with China. Last February, the US and the Philippines announced that the US would gain access to four more bases in the Philippines close to Taiwan, and that they would resume joint patrols in the South China Sea.
In April, the US and the Philippines held their largest joint military exercise in decades, announced plans to conduct joint jet fighter exercises for the first time since 1990, and agreed to establish an intelligence-sharing framework. This May, President Marcos Jr. made an official visit to Washington, DC, which was the first such visit by a Philippine president in more than 10 years. This was followed by the establishment of the Bilateral Defense Guidelines to modernise and strengthen the alliance. Manila has also proven its resilience to Chinese economic coercion that could follow a missile-hosting agreement.
A rotational deployment of US ground-based anti-ship missiles to Philippine bases would constitute a major deepening of US-Philippines defence cooperation and could bolster regional deterrence. Given contention in the Philippines over the presence of US forces, in addition to likely concerns over how China may respond, it cannot be assured that Manila would agree. However, growing concerns over eroding deterrence across the Taiwan Strait, coupled with Manila’s shift in foreign policy, could make it worthwhile for Washington to approach the Philippines over hosting this missile capability.
DISCLAIMER: All views expressed are those of the writer and do not necessarily represent that of the 9DASHLINE.com platform.
Author biography
Rupert Schulenburg is a Defense Strategy and Planning Intern at the Stimson Center. He holds an MPhil in International Security Studies from the University of St Andrews and a BA (Hons) in International Relations from the School of Oriental and African Studies (SOAS), University of London. His research focuses on security and regional dynamics in the Indo-Pacific, US alliances, partnerships, force posture, and US-China competition. Image credit: Wikimedia.