As missile threats become more numerous, diverse and technologically sophisticated, a recent US Senate hearing has exposed growing concerns that US homeland missile defenses are increasingly out of step with the realities of modern warfare.
Assistant Secretary of Defense Marc Berkowitz issued a scathing statement ASSESSMENT of the homeland’s current capabilities, stating that the US relies on a “very limited” land-based, single-layer defense system designed specifically to counter a small-scale intercontinental ballistic missile (ICBM) attack from North Korea.
He stressed that this architecture offers only “very limited capabilities” against other ballistic missile threats. More critically, Berkowitz warned that the US currently has “no defenses against hypersonic weapons or cruise missiles today,” later clarifying that he was referring to advanced cruise missiles.
The Ground Medium Defense (GMD) is currently the only system capable of defending the US homeland against ICBM attack. It uses integrated communications networks, fire control systems, globally distributed sensors and ground-based interceptors (GBIs) that can detect, track and neutralize ballistic missile threats.
However, GMD’s performance can leave a lot to be desired. The data from the Missile Defense Advocacy Alliance (MDAA) show that between 1999 and 2023, 21 GMD tests were conducted, resulting in 12 hits and 8 misses, with a success rate of 57%.
Delving further into the limitations of the GMD system, Robert Peters notes in a March 2026 Heritage Foundation REPORT that the US deploys 44 GBI for the GMD system. Peters points out that the GMD is limited both numerically and technologically, making it very limited in defending against more sophisticated or multi-missile attacks, including those with multiple warheads or advanced countermeasures.
US Defense Intelligence Agency (DIA) ASSESSMENT as of March 2025 shows that conventional ICBMs remain the primary threat to the US homeland, with China having about 400, Russia about 350, and North Korea 10 or fewer, due to their numbers and their ability to hit any part of the US. He notes that submarine-launched ballistic missiles (SLBMs) pose an additional risk, as no part of the US is beyond their reach.
The DIA assessment also shows that hypersonic weapons—estimated at about 600 for China and 200 to 300 for Russia—complicate interception due to their speed and maneuverability, while land-attack cruise missiles (LACMs), estimated at 1,000 for China and 300 to 600 for Russia for detection and detection of low-flying signatures.
He further points to developing systems such as partial orbital bombardment systems (FOBS), which can approach from unexpected trajectories, including over the South Pole, to bypass early warning systems.
Together, these capabilities illustrate the scale and diversity of threats that current US missile defenses, such as GMD, were not designed to handle.
Against such threats, the US homeland missile defense remains very limited. Using an ICBM strike as a performance indicator, an American Physical Society (APS) in February 2025 REPORT notes that, despite more than $400 billion spent since 1957, no missile defense system is effective against realistic ICBM threats.
The report notes that intercepting a single nuclear-armed ICBM or its warhead in flight is extremely challenging, given the short engagement windows and the difficulty of distinguishing warheads from decoys and other objects in space.
He adds that US missile defense systems are designed to address limited threats, such as small-scale attacks, and would face significant difficulties against more complex or larger attacks.
The report states that missile defense must be near perfect to be effective, as even a penetrating nuclear warhead defense would be catastrophic, yet current capabilities remain low and are likely to remain so for at least 15 years.
Taken together, these findings suggest that US missile defenses are structurally limited not only by scale, but by fundamental technical limitations. The Trump administration’s Golden Dome missile defense project aims to address these gaps, but faces significant technical, cost and feasibility questions.
Golden Dome is a US initiative to build a layered “system of systems” that integrates space-based, air-based, land-based and sea-based missile defenses to protect the US homeland against ballistic, hypersonic and cruise missiles, as well as other air threats.
However, Jeff Hecht writes in one ITEM this month for the Bulletin of the Atomic Scientists that Golden Dome faces severe time constraints, with sensors unable to confirm an ICBM trajectory until about 75 seconds after launch, leaving only 25-35 seconds to deploy and engage before an interceptor is launched, while multiple decoys and warheads further complicate interception.
He adds that the system faces major feasibility challenges, noting that estimates suggest that roughly 40,000 space-based interceptors would be needed to counter even a limited number of 10 ICBMs, with satellites needing replacement every about 5 years due to orbital decay.
He also highlights the system’s potentially huge costs, citing US estimates that rise to about $185 billion for initial deployment and analyzes that suggest total costs could reach $3.6 trillion over 20 years, raising serious doubts about affordability and practicality.
Against this background, Jeffrey Lewis argues in a May 2025 Scientific American ITEM that the Golden Dome is “fantasy” rooted in the belief that the US can buy its way out of nuclear vulnerability. He argues that while nuclear vulnerability is difficult to accept, it is the logic of mutually assured destruction (MAD) that has prevented nuclear war.
Despite those criticisms, Kari Bingen EVIDENCE in a January 2026 Center for Strategic and International Studies (CSIS) commentary that Gold Dome can be justified because the threat environment has changed profoundly, leaving the US homeland increasingly vulnerable to a wider range of large-scale, diversified and coordinated missile and air threats.
Bingen claims that the Golden Dome is not about perfect defense, but about limiting damage, complicating the opponent’s planning and raising the threshold for attack, thereby strengthening deterrence.
She adds that by integrating existing systems into a layered architecture, the system could offer policymakers more response options beyond nuclear retaliation, making it a necessary evolution rather than an unrealistic pursuit of invulnerability.
Going forward, US homeland missile defense will be defined less by its ability to stop direct attacks than by how effectively it reshapes an adversary’s calculus in an increasingly complex and contested threat environment.
However, the evidence points to a harsher reality: a defense architecture that must be near-perfect to function is inherently vulnerable to failure, especially when faced with larger or more sophisticated salvos.
As the relatively unsophisticated missiles and drones in the Iran war have shown, US and Israeli defenses can be saturated and penetrated when attacked in sufficient numbers. At its core, this is a problem of physics and statistics – interceptor-based systems are finite, expensive, and vulnerable to overload, while attackers can scale more cheaply.
Absent a shift toward fundamentally different technologies, such as guided-energy weapons, the current U.S. approach to missile defense remains, at its core, a losing proposition—one that can mitigate the risk, but not eliminate it.
