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Editor’s Note: This is the second article in a two-part series exploring the Golden Dome for America proposal. Please also read the first, “Golden Dome Is Technologically and Financially Infeasible.”
Golden Dome is an ambitious proposal for a comprehensive, layered defense, with ground, sea, and space-based elements. It is supposed to protect the United States, its allies, and deployed forces from attacks by ballistic missiles, cruise missiles, hypersonic boost-glide vehicles, aircraft, and drones launched by any adversary, including peer adversaries. The Golden Dome executive order also mandates further development of capabilities to defeat an adversary’s missiles before they are launched.
A key goal of the Golden Dome proposal is to defend the United States against nuclear-armed intercontinental-range ballistic missiles and submarine-launched ballistic missiles launched by Russia, China, or North Korea. But there is no prospect of building an effective defense against long-range ballistic missiles for the foreseeable future, and trying to build a system that would look even remotely effective on paper would cost hundreds of billions to trillions of dollars.
Deploying a defense against long-range ballistic missiles that is ineffective will not only waste resources, but will also put the United States in greater danger. How could a system be both ineffective and dangerous? Because potential adversaries will react not only to the current system’s perceived capabilities, but also to what they think the defense might be able to do in the future. Even if the defense’s existing capabilities are limited, the fact that a program of record has a budget in the hundreds of billions of dollars and an extremely ambitious objective will prompt U.S. adversaries to take actions that will increase the risk of nuclear war, and the consequences if a war occurs. These actions include deploying more nuclear weapons to overwhelm the defense and new weapons to evade or destroy the system. In addition, deploying a boost-phase intercept defense — even if it were feasible — would be highly provocative and turn crises into faster, more automated, more mistake-prone events that are more likely to lead to a nuclear war.
Whether or not a working system is built, the policy mandate and the attempt to build a comprehensive defense against long-range ballistic missiles will almost certainly increase the nuclear threat faced by the United States. U.S. adversaries will seek to deploy more strategic missiles and warheads and new types of weapons that can evade, overwhelm, or directly attack the missile defenses. These include new delivery systems, such as boost-glide vehicles and fractional orbital bombardment systems; additional warheads on existing missiles and countermeasures to make sure their nuclear weapons are able to penetrate the defense; and cyber and anti-satellite weapons.
The simplest way to counter a missile defense system is to add more warheads to existing missiles or increase the number of missiles in one’s arsenal. Since February 2026, the United States and Russia are no longer legally bound by the New Strategic Arms Reduction Treaty limits. Russia could rapidly deploy more nuclear warheads on its existing missiles, and may do so to be certain it can overwhelm a U.S. missile defense. China is reportedly expanding its nuclear arsenal.
When the United States withdrew from the Anti-Ballistic Missile Treaty and began to deploy its current strategic missile defense, it created a powerful incentive for Russia and China to accelerate development and deployment of weapons designed to evade or penetrate missile defenses. In 2018, Russian President Vladimir Putin announced the development of new delivery systems in direct response to the U.S. withdrawal from the Anti-Ballistic Missile Treaty and its deployment of a strategic missile defense. These systems include Sarmat, a heavy long-range ballistic missile that has a fast-burning motor to complicate detection and tracking, and possesses enough range to attack the United States from the south; Avangard, a hypersonic boost-glide vehicle designed to evade missile defenses or attack forward-based elements; Poseidon, an uncrewed, nuclear-powered underwater vehicle armed with a large nuclear weapon capable of destroying U.S. coastal cities; and Burevestnik, a nuclear-armed, nuclear-powered cruise missile designed to attack U.S. cities at any time from any direction. Russia is also developing the “Yars-M” intercontinental ballistic missile, which can deploy its warheads on separate final stages, each with its own guidance, greatly increasing the challenge for a boost-phase defense.
China is pursuing a hypersonic boost-glide vehicle that could target forward-based missile defense infrastructure and has demonstrated the technology for a fractional orbital bombardment system that would insert a re-entry vehicle-carrying spacecraft into a low-Earth orbit from which it could strike a target from an undefended direction.
Both Russia and China have deployed or tested ground-based direct ascent anti-satellite weapons and co-orbital technologies that could be weaponized to individually target the space-based elements of a missile defense system. The possible deployment of space-based missile defenses by the United States gives Russia strong incentives to develop and deploy anti-satellite systems capable of damaging or destroying larger numbers of U.S. satellites. The United States has claimed that Russia is currently developing an on-orbit nuclear-armed anti-satellite weapon. The detonation of a nuclear weapon in space would immediately damage or destroy unhardened satellites in the line-of-sight of its radiation, and could damage the sensors and electronics of many more over subsequent weeks and months. This could potentially disable space-based interceptors or supporting sensors without having to target them individually.
China is reportedly considering raising the standard alert level of its long-range ballistic missiles to increase their chances of successfully being launched if they are attacked, but this would also increase the risk they could be launched by mistake.
The risk generated by deploying defensive systems, even if they are ineffective, is heightened by having a policy that does not preclude a nuclear first strike and explicitly invokes “left of launch” attacks. The adversary’s threat perception is further increased by the United States maintaining a strategic posture that includes conventional strike, space and cyber weapons, and other weapons that could help support a disarming first strike.
Taken together, these actions would provoke U.S. adversaries to deploy more (and more effective) strategic nuclear weapons to ensure their retaliatory capability, making the United States less safe.
Launching a constellation of tens of thousands or even more orbiting interceptors would be a provocative weaponization of space at a faster pace and larger scale than any deployment of military space technologies to date. U.S. adversaries would almost certainly develop ways to counter such a system, which would threaten their nuclear deterrent and other vital systems. In fact, they already have.
Russia, China, and North Korea have already tested, or are developing, anti-satellite weapons that could attack space-based missile defense interceptors and the other assets such a system would need. U.S. adversaries could decide it would be better to prevent an American space-based interceptor system from becoming operational, instead of facing it once it’s complete. Both Russia and China have have demonstrated ground-based direct-ascent missiles that could be used to preemptively challenge construction of a space-based missile defense system by destroying interceptors. Hence, even attempting to build such a system would be very dangerous. Anti-satellite weapons could also be used to damage a deployed space-based interceptor system to make an attack using a salvo of long-range ballistic missiles more successful.
Space-based interceptors could themselves be designed to destroy satellites as well as missiles, and would be capable of reaching satellites in geosynchronous orbits. Deployment of large numbers of anti-satellite weapons would be highly risky, spur adversaries to respond in kind, and undermine efforts to create a stable, secure space environment.
Deploying a boost-phase missile defense system would significantly compress decision times. The earliest such a system could confidently fire its interceptors is at least 75 seconds after an attacking long-range ballistic missile has been launched. For most current long-range ballistic missiles, the interceptors would then have only 45 to 75 seconds left to reach the missile and collide with it before it deploys its warheads. Any additional time devoted to assessment and deliberation before firing interceptors would decrease their fly-out time and increase the demands on the space-based interceptor system.
But as we have previously explained, the time pressure is likely to be even more brutal. Even today, a submarine-launched ballistic missile could strike a U.S. city after burning for only about 100 seconds. In this case, interceptors would have only 25 seconds of fly-out time to reach the missile while its motors are still burning, a practical impossibility even if the defense fired interceptors in less than 30 seconds.
If the United States were to deploy a boost-phase intercept system, adversaries could respond by deploying fast-burn long-range ballistic missiles with full burn times as short as 50 to 100 seconds; launching them from sites closer to United States cities; flying them on faster, depressed trajectories; and designing them to be harder to intercept. In fact, U.S. adversaries appear to be doing this already.
Crisis decision times measured in tens of seconds would require the United States to pre-delegate to lower-level commanders the authority to fire interceptors and push the United States toward automating threat assessments and launch decisions. This would raise the risk of mistakes, misunderstandings, and escalation to nuclear war.
Motivated by the difficulty of building an effective strategic missile defense, especially against more than a small number of missiles, the Golden Dome executive order mandates the development of capabilities to defeat adversaries’ missiles before they can be launched. This is sometimes referred to as a “left of launch” attack. An example would be carrying out a surprise attack on an adversary’s leaders and communications, command, control, and battle management systems, as well as their nuclear-armed missiles, if it appears they are or could be preparing to attack the United States or its allies.
A first strike of this kind could precipitate a nuclear war that would kill tens or hundreds of millions of people. The doctrines and capabilities that could, in principle, make a left-of-launch or a “damage limitation” attack possible would include persistent overhead imagery to facilitate tracking and targeting of mobile missiles, sophisticated anti-submarine warfare capabilities, precision-guided long-range conventional weapons that can target command and control facilities and potentially damage missile silos, and strategic missile defenses. Developing or deploying these capabilities would increase adversaries’ perception of a threat, provide incentives for early escalation to “use it or lose it,” and reduce decision times still further.
For the foreseeable future, a preemptive strike on U.S. adversaries would not be able to destroy all threatening missiles. Even a “left of launch” strategy would require a highly effective strategic missile defense to make a disabling first strike plausible. To avoid creating a “hair trigger” situation, it is therefore critical that all parties understand that any deployed strategic missile defense has only a limited capability against even a small number of missiles. But the current U.S. strategic missile defense system, the Ground-based Midcourse Defense, has been described over and over by American officials across administrations as working nearly perfectly, even though it has not performed well even in limited tests. Unwarranted confidence in a missile defense system is also dangerous in another way: it can lead the command authority to make catastrophic mistakes.
Historically, arms control and disarmament agreements have stabilized the nuclear arms race, enabled risk reduction measures, and greatly reduced nuclear arsenals, reducing the nuclear threat. From 1970 to 2010, the Anti-Ballistic Missile Treaty (until 2002) and a series of successful nuclear arms reduction treaties reduced the number of nuclear weapons possessed by the United States and Russia from about 70,000 in the mid-1980s to about 8,000 today. These agreements produced the only large reduction in the nuclear threat to the United States and Russia since nuclear weapons were first deployed.
The failure to extend or replace the existing New Strategic Arms Reduction Treaty limits on U.S. and Russian strategic nuclear forces or to constrain Chinese strategic forces, combined with the absence of any limits on the deployment of tactical and strategic nuclear warheads, strategic missile defenses, and space weapons, is increasing the nuclear threat and the risk of nuclear war.
The proposed Golden Dome provides no real solution to this problem. It would not provide meaningful protection, but would instead waste resources and divert attention from more effective approaches. Indeed, pursuing a missile defense program of Golden Dome’s proposed scope is likely to make diplomatic negotiations more challenging, as Russia has long insisted that strategic defenses should be included in such discussions, whereas the United States has refused to consider limiting such systems. As difficult as nuclear arms reduction agreements are to negotiate, history points to them as the only way to reduce the threat.
Building new strategic missile defenses like those in the Golden Dome proposal would not only be exorbitantly costly and ineffective, it would also be very dangerous — even if they were built with the best intentions. Deploying strategic missile defenses will motivate U.S. adversaries to deploy even more nuclear weapons or technologies to counter these defenses, or plan an attack larger than they would otherwise plan in order to achieve the desired effect.
Launching the many tens of thousands of orbiting interceptors that a space-based boost-phase defense would require would be provocative and destabilizing. Worse, deploying a boost-phase intercept system would compress decision times in a crisis to tens of seconds or less. Such a system can fail catastrophically by creating unwarranted confidence in the ability to defend against a nuclear attack and turning crises into faster, more automated, more mistake-prone events that are more likely to end in nuclear war.
Nuclear arms control agreements remain the only historically successful approach to reducing the nuclear threat to the United States.
Frederick Lamb is the Brand and Monica Fortner Chair of Theoretical Astrophysics Emeritus and a core faculty member in the Program in Arms Control and Domestic & International Security at the University of Illinois. He co-chaired the American Physical Society’s 2003 study of Boost-Phase Missile Defense and chaired its 2025 study of Strategic Ballistic Missile Defense. He is a member of the American Academy of Arts and Sciences and a fellow of the American Physical Society.
Laura Grego, Ph.D., is a senior scientist and the research director in the Global Security Program at the Union of Concerned Scientists. She is a fellow of the American Physical Society, co-chaired its 2025 study of Strategic Ballistic Missile Defense, and was awarded its Leo Szilard Lectureship Award in 2023.
Image: DOD Defense Visual Information Center via Wikimedia Commons.
