Taiwan has announced a new deal to upgrade its US-supplied Patriot missile defense system. Image: Twitter

The US and Taiwan have renewed a missile engineering contract to upgrade the self-governing island’s Patriot missile defense systems against China’s growing missile threats and overflights.

The Taipei Times reports that the contract was announced by Taiwan’s Ministry of Defense on August 11, with Focus Taiwan citing a notification regarding the contract on the Taiwan Government e-Procurement System website. Currently, Taiwan operates the Patriot Advanced Capability 2 (PAC-2) and PAC-3 Guided Enhancement Missiles (GEM) systems.

The South China Morning Post reported that the US$83 million contract, signed by Taiwan’s military and the American Institute in Taiwan, the de facto US embassy on the island,  would help to assess and improve the performance of Taiwan’s Patriot missile batteries for the next four and a half years.

Focus Taiwan reported that the missile upgrade program runs from July 20, 2022, to December 31, 2026. Moreover, it notes that Taiwan’s current Patriot missile inventory consists of MIM-104F and GEM missile rounds.

The South China Morning Post report notes that Taiwan will upgrade its PAC 2 missiles to PAC 3 GEM standards with longer-range missiles. The report also notes that the PAC 3 GEM has two types of missiles, with the extended range version capable of intercepting ballistic missiles at 600 kilometers.

In addition to upgrading legacy systems, Focus Taiwan notes that in 2021 Taiwan also purchased PAC-3 Missile Segment Enhancement (MSE) missiles, with the first batches to be delivered in 2025 and 2026.

The same news source notes that the MIM-104F can intercept ballistic missiles, while the MSE variant has a longer range than the standard round, covering the middle area between the MIM-104F and terminal high altitude air defense systems with Taiwan receiving this upgrade between 2025 and 2026.

A Patriot Advanced Capability-3 (PAC-3) missile launcher. Credit: US Army/ commons.wikimedia.org.

The US-Taiwan contract aims to maintain the original combat capability of Taiwan’s Patriot missile defense systems, but does not increase the number of missiles Taiwan possesses, notes Lu Li-shih, a former instructor at the Taiwanese Naval Academy at Kaohsiung, as cited by the South China Morning Post.

However, China’s recent military exercises and missile drills over Taiwan in the aftermath of US House of Representatives Speaker Nancy Pelosi’s recent visit to the self-governing island may have exposed holes in Taiwan’s missile defenses.

Despite being advertised as one of the world’s most advanced missile defense systems, the Patriot may be ineffective in certain combat situations. For example, in a 2018 Foreign Policy article, Jeffrey Lewis points out the ineffectiveness of Saudi Arabia’s Patriot missile systems against the ballistic missiles fired by Houthi rebels in Yemen.

Lewis also points out that the US Army may have manipulated figures about the Patriot’s performance during the 1991 Gulf War, initially claiming near-perfect performance intercepting 45 out 47 ballistic missiles but later revising this figure down to 50% and after that expressing “higher confidence” in just a quarter of intercepts.

With questionable reliability in intercepting ballistic missiles, the Patriot system may have limited capabilities against fighter jets as well. While the South China Morning Post noted that Taiwan had used the Patriot’s high-powered radars to track People’s Liberation Army (PLA) activities in the Taiwan Strait, Patriot missile interceptors are not equipped to counter fighter jets, notes defense analyst Kris Osborn in The National Interest.

Osborne mentions that although the Patriot system can track and destroy ballistic missiles and multiple maneuvering targets, its capabilities fall short of shooting down incoming fighter jets. The writer did not mention specifics about the system’s limitations but they most likely stem from the Patriot’s limited capabilities against low-flying targets, as shown by the successful attacks of Iranian drones against Saudi oil facilities, despite Riyadh’s Patriot missile system.

Defense analyst Stephen Bryen notes in Asia Times additional glaring limitations of the Patriot system. First, Bryen mentions that Patriot interceptors are fired when an incoming missile is at its terminal phase when the missile is just a few thousand feet above the ground and near its target. At that phase, the incoming missile can jettison a smaller and harder to intercept warhead or release decoys such as chaff to confuse missile defense radars.

Second, he mentions that the Patriot may have limited target discrimination capabilities. Citing Saudi Arabia’s experience with the system, Bryen notes that the Patriot may have difficulty distinguishing between the main body of ballistic missiles and their separated warheads. Finally, Bryen mentions that even if the Patriot system worked, it would be pointless if the system struck a missile body instead of its lethal warhead.

A so-called highly-lofted trajectory ballistic missile attack by China may blunt the effectiveness of Taiwan’s Patriot missile systems. Indeed, such limitations may have caused Japan to cancel its plans to procure two Aegis Ashore systems in 2020.

The Missile Defense Agency conducts the first intercept flight test of a land-based Aegis Ballistic Missile Defense weapon system from the Aegis Ashore Missile Defense Test Complex in Kauai, Hawaii. Photo: US Missile Defense Agency / Handout / Leah Garton

A 2020 article in the Journal of Indo-Pacific Affairs notes that the Aegis Ashore system or ballistic missile defense (BMD) is generally incapable of defending against ballistic missiles fired in a highly-lofted trajectory – although it mentions that software upgrades may help to mitigate this limitation in the future.

The same article mentions that North Korea could fire medium and intermediate-range missiles at higher angles to strike targets such as South Korea and Japan, resulting in an extremely high terminal phase velocity and undermining the effectiveness of any missile defense system. It also notes that the Patriot missile system cannot defend against such an attack and that no current missile defense system is optimized to defend against such.

Moreover, the article notes that in such an attack missile defense radars often lose track of the target when it reaches its apex and regains track of it too late for interceptor missiles to hit their mark.

Furthermore, as interceptor missiles are flying against gravity, it is much harder for them to re-adjust, catch up and hit the target at the right angle, in contrast to the constantly-accelerating hostile missile.

Moreover, the Patriot system may have numerous limitations in the Taiwan Strait operating environment. For example, the Eurasian Times reported on August 7 that the PLA launched 11 Dong Feng missiles into the waters around Taiwan, noting that the island did not use its Patriot interceptors against the incoming missiles.

The report notes multiple reasons for Taiwan’s apparent standing down to China’s ballistic missile launches. First, China’s ballistic missiles flew above the Karman Line, which is 100 kilometers above Earth and is in the airspace limit. Simply put, Taiwan did not intercept China’s missiles since they were not in its airspace but rather in outer space.

Second, the source notes that the boost phase of China’s Dongfeng missiles takes place within China’s territory and is out of range of Taiwan’s defenses. Although the missiles’ mid-course phase is above Taiwan, it is outside Taiwan’s airspace while in outer space.

While Taiwan can intercept China’s ballistic missiles in their terminal phase, such an interception has a short window of time considering the Patriot’s potentially mediocre performance as shown in Saudi service and the possibility of a highly-lofted trajectory attack.

Third, the Eurasian Times mentions the cost of Patriot missile interceptors may have prevented Taiwan from using its limited stock of rounds. The source notes that one Patriot interceptor costs US$16 million, compared to one of China’s Dongfeng missiles, which costs around $660,000.

A formation of Dongfeng-17 missiles takes part in a military parade during the celebrations marking the 70th anniversary of the founding of the People’s Republic of China at Tian’anmen Square in Beijing. The Ukraine war may be fixing PLA leaders’ eyes on more basic capabilities – like mobile infantry. Photo: Xinhua / Mao Siqian

The high cost of Patriot interceptors could be a limitation in acquiring more missiles to counter multiple ballistic missiles, which may have penetration aids and decoys that force Taiwan to waste its missiles in preparation for subsequent air and missile strikes.

Finally, the advent of China’s hypersonic weapons may also render Taiwan’s Patriot system obsolete. On July 31, China’s state-run media outlet Global Times reported that China conducted a test firing of its DF-17 hypersonic missile in a veiled warning to Pelosi’s anticipated visit to Taiwan on August 2.

As no current missile defense system is effective against hypersonic weapons, Taiwan’s Patriot missiles, given their various limitations, may give a false sense of security and encourage military planners on both sides to take even more escalatory actions.

In future, China may ramp up missile tests and combat aircraft overflights to expose vulnerabilities in Taiwan’s defenses, prompting the latter to respond with military drills and further stoking already tense cross-strait relations.