Fully Fund the Guam Defense System

5082436 (1)

The Biden administration talks tough when it comes to competing with China and taking the necessary steps to reinforce America’s defense posture in the Indo-Pacific. However, it is not clear whether the administration is prepared to match resources with words. Following an anemic defense budget proposal, the Biden Pentagon is now ignoring — or, at least, slow-rolling — analysis that makes clear that the Guam Defense System represents an essential and urgent priority for American forces in the region.

House appropriators cut funding this month for efforts designed to protect American citizens and U.S. military bases in Guam from an increasingly formidable Chinese missile threat. The appropriators say they support improved missile defenses for Guam, but they cited the Pentagon’s failure to submit a required report that was due on May 1 as part of the justification for the cut. That is a short-sighted rationale given the rapidly growing missile threat from the People’s Liberation Army and the Pentagon’s persistent lack of responsiveness to Indo-Pacific Command’s repeated requests for funding to better defend Guam. The decision to cut funding also runs counter to the congressional authorizers’ commitment to improving defenses in the Pacific.



If these cuts are retained in the final legislation, they will delay the delivery of vital capabilities desperately needed to address both current Chinese ballistic and cruise missile threats and hypersonic capabilities Beijing is expected to deploy by 2026. That would leave Guam vulnerable longer than necessary and invite aggression from Beijing.

Congress should provide full funding for the Guam Defense System, consistent with the Pacific Deterrence Initiative. At a minimum, Congress should authorize and fund preparatory measures necessary for any new missile defenses in Guam, whether the Guam Defense System or another system. Those measures should include the environmental impact statement and the completion of site surveys on Guam, as well as pushing forward research and development efforts related to the many sensors, weapons and warheads required. This includes the Glide Phase Interceptor, Standard Missile-6 systems, long range precision strike systems, and the Army’s Integrated Air and Missile Defense Battle Command System.

China’s Missile Threat Against Guam

Indo-Pacific Command calls Guam the “most important operating location in the Western Pacific” — one the United States “must fight from” but “must also fight for.” It is easy to see why. Besides the roughly 170,000 U.S. citizens living there, Guam is home to Anderson Air Force Base, a submarine base, a new Marine Corps base, and numerous logistics and prepositioned stores.

U.S. military forces in Guam are not just a necessary forward-deployed capability. They also represent a powerful symbol that America is a Pacific power and is willing and able to defend its interests in the region. In the event of a conflict in the Taiwan Strait or elsewhere, Beijing knows that the U.S. military will need facilities on Guam to project military power and sustain it once there.

China fields a number of ballistic and cruise missiles that can target Guam. The new commander of Indo-Pacific Command, Adm. John Aquilino, told Congress in March in advance of his nomination hearing that Beijing has sprinted to improve the “range, survivability, accuracy, and lethality” of its missiles. China’s arsenal includes the land-based Dong Feng-26, a road-mobile intermediate-range ballistic missile sometimes called the “Guam killer.” They also possess cruise missiles that could be launched at Guam from any direction using H-6 bombers, submarines, or surface warships. And Beijing is also developing a hypersonic glide vehicle that could target Guam when employed in conjunction with a ballistic missile such as the Dong Feng-17.

Aquilino’s predecessor at Indo-Pacific Command, Adm. Phil Davidson, warned last year that the missile threat to Guam will only get worse by 2026 and “will require us to have a much more robust capability than the combination of [the Terminal High Altitude Area Defense missile defense system], which is deployed there now, and an Aegis ship in response can provide.”

That is why Indo-Pacific Command has made clear in successive annual reports to Congress that the Guam Defense System represents the combatant command’s top unfunded priority. The system would provide a 360-degree persistent and integrated air defense capability for Guam. That would better protect Guam and free up Aegis-equipped warships needed elsewhere.

The Department of Defense has completed (but not delivered to Congress) a study that will inform what the Guam Defense System architecture will actually look like, but it will probably consist of a land-based version of the Aegis Combat System, a solid-state radar, Mark 41 Vertical Launching Systems, and Standard Missiles (SM-2, SM-3, and SM-6). These elements could be integrated — via the Command, Control, Battle Management, and Communications System — with the Patriot Missile Defense System, the existing Terminal High Altitude Area Defense system in Guam, and perhaps the Lower Tier Air and Missile Defense Sensor as well as other potential sensors and shooters distributed throughout Guam and nearby islands.

In other words, the Guam Defense System is a hybrid solution, not a carbon copy of the Aegis Ashore system the U.S. military has deployed in Romania and is building in Poland. Describing this system, therefore, as Aegis Ashore only paints part of the picture and has created some confusion.

In a July 9 op-ed, Adm. (ret.) Harry Harris, himself a former commander of Indo-Pacific Command, reiterated the urgent need for improved missile defenses for Guam. But Harris also expressed concern that an Aegis Ashore system modeled on the ones in Romania and Poland would be inadequate.

Therein lies a major point for Congress to understand. Indo-Pacific Command and the Missile Defense Agency do not seek to copy and paste the Aegis Ashore systems from Europe for Guam. To be sure, there will likely be some similarities, but there would also be many differences in the system built in Guam, based on the island’s geography and the different missile threats the system would seek to address.

To begin with, the Guam Defense System would be a distributed system, making it more survivable. Moreover, Vice Adm. Jon Hill, the director of the Missile Defense Agency, has suggested that key components of the system in Guam could be underground or mobile. “There are ways to do that,” Hill said last month. “It’s not a big stretch.”

Harris also argues that an “essential attribute” of the system in Guam will be an open architecture “to ensure interoperability of current and future radars and interceptors across the services.” He also emphasizes that it should be “persistent, scalable, robust enough to tackle the full spectrum” of missile threats to Guam.

Here’s the point: What Harris says Guam needs is what the hybrid Guam Defense System solution will, in fact, provide.

The Aegis system has already integrated many sensors and weapons, and others could be added quickly. As a result, the Guam Defense System hybrid solution would be able to defend against ballistic missile threats and cruise missile threats (with the right sensors). Moreover, an aggressive effort is already underway to ensure Aegis systems can cope with hypersonic threats. The Guam Defense System could also be used to command and control supporting offensive systems, which could be mobile and dispersed throughout Guam and nearby islands. This mix of offensive and defensive systems would make the defense infrastructure in Guam more survivable and a more effective deterrent against China.

Anticipating Counterarguments

Some may respond to this analysis by suggesting that Beijing could simply overwhelm any new missile defenses on Guam.

There are several problems with that argument. At its core, accepting this argument would essentially leave an American territory populated by 170,000 U.S. citizens dangerously and increasingly unprotected. Setting aside the moral and political implications of such a position, failing to address growing missile threats to Guam would turn the island into a hostage China could use to coerce Washington to not respond to Beijing’s aggression in the Taiwan Strait or elsewhere.

In such a scenario, Beijing could make clear that any U.S. response in the Taiwan Strait would force the People’s Liberation Army to pummel Guam with missiles. Having failed to take sufficient action to defend Guam, American leaders would be forced to take that threat seriously. This is not some outlandish scenario and is actually similar to the first vignette of concern cited by the bipartisan congressionally mandated National Defense Strategy Commission in its 2018 report.

Failing to respond to the growing missile threat to Guam also ignores one of the principal purposes and benefits of missile defense. One of the great benefits of missile defense is that it creates doubt in the minds of potential adversaries as to whether an attack would accomplish its key objectives. By doing so, missile defense increases the chances that an aggressor may not undertake the attack in the first place.

Missile defenses can provide valuable time to launch a more effective and potent counter-offensive. The aggressor’s missile barrage may eventually destroy most of its targets, but the protection missile defenses provide, even if only temporally, forces an adversary considering aggression to contemplate the costs a counterattack would inflict. In those ways, missile defenses contribute to what is called deterrence by denial (the aggressor is not confident it can achieve the desired objectives) and deterrence by punishment (the aggressor fears the counterattack might be too costly) — both of which incentivize an adversary to not launch the attack in the first place.

And, to be clear, no one is arguing that the “as built” Guam Defense System will be a missile defense panacea for all time. It would be an important first step that can be implemented in a timely fashion in response to a specific emerging threat. Over time, the Guam Defense System can and should be modernized iteratively with improved hardware and software — both defensive and offensive.

What Congress Should Do

So, what’s to be done? Congress should fully support the Guam Defense System requests for this year and not delay action until the next budget cycle.

The combatant command closest to the threat from China has made clear what is urgently needed to defend Guam and deter China, and the Missile Defense Agency submitted its analysis to the Office of the Secretary of Defense weeks ago. Congress should not deprive the military of what it clearly needs just because the Defense Department decided to ignore a statutory requirement and fail to submit a report.

Beijing’s missile threat to Guam is growing, and there is no time to waste. Congress should act.



Bradley Bowman is the senior director of the Center on Military and Political Power at the Foundation for Defense of Democracies. He spent nearly nine years working in the U.S. Senate, including six years as the top defense advisor to Sen. Kelly Ayotte, then the senior Republican on the Armed Services Readiness and Management Support Subcommittee. He has also served as a U.S. Army officer, Black Hawk pilot, and assistant professor at West Point.

Mark Montgomery is the senior director of the Center on Cyber and Technology Innovation and a senior fellow at the Foundation for Defense of Democracies. He previously served as policy director for the Senate Armed Services Committee under the late Sen. John S. McCain and is a retired rear admiral in the U.S. Navy.

Image: Army (Photo by Capt. Adan Cazarez)