Golden Dome Is Technologically and Financially Infeasible

For as long as nuclear-armed, intercontinental ballistic missiles and submarine-launched ballistic missiles have existed, strategists and engineers have pursued a seductive idea: a shield effective enough to diminish — or even block — a ballistic missile attack.

自从核武器、洲际弹道导弹和潜射弹道导弹存在以来，战略家和工程师就一直在追求一个诱人的想法：一个足以有效削弱甚至阻止弹道导弹攻击的防护罩。

The appeal is obvious.

其吸引力是显而易见的。

A state that could reliably intercept ballistic missiles could protect its cities from these terrifying weapons and reduce its adversaries’ leverage.

一个能够可靠拦截弹道导弹的国家可以保护其城市免受这些可怕武器的侵害，并降低对手的影响力。

But defenses against strategic ballistic missiles have a long history of disappointments.

但战略弹道导弹的防御长期以来都令人失望。

Over roughly seven decades, the United States has spent more than $500 billion (in 2025 dollars) on missile defenses, much of it to defend against intercontinental ballistic missiles.

大约七十年来，美国在导弹防御上花费了超过 5000 亿美元（以 2025 年美元计算），其中大部分用于防御洲际弹道导弹。

And yet, the ability of any of these systems to intercept even a single missile or warhead under the conditions expected during a nuclear attack has not been demonstrated .

然而，这些系统在核攻击预期条件下拦截单个导弹或弹头的能力尚未得到证实。

Most recently, the Trump administration has proposed “Golden Dome” — an ambitious proposal for a comprehensive, layered defense with ground, sea, and space-based elements.

最近，特朗普政府提出了“金穹”——一项雄心勃勃的提议，旨在建立包含地面、海上和天基要素的全面、分层防御。

It is supposed to protect the United States and its allies and deployed forces not only against attacks by ballistic missiles, but also by cruise missiles, hypersonic boost-glide vehicles, aircraft, and drones launched at any time from anywhere by any adversary, including peer adversaries.

它的目的不仅是保护美国及其盟国和部署的部队免受弹道导弹的攻击，还包括任何对手（包括同等对手）随时随地发射的巡航导弹、高超音速助推滑翔飞行器、飞机和无人机的攻击。

There is no prospect of deploying a missile defense system capable of successfully defending against a major ballistic missile attack by Russia and China for the foreseeable future.

在可预见的未来，部署能够成功防御俄罗斯和中国重大弹道导弹袭击的导弹防御系统的前景是不可能的。

Such a system would have to be able to destroy hundreds or thousands of nuclear-armed long-range ballistic missiles or their warheads in the face of sophisticated countermeasures, dozens of decoys, and salvo tactics, as well as new delivery systems specifically designed to defeat it.

这样的系统必须能够在复杂的对抗措施、数十个诱饵和齐射战术以及专门设计用于击败它的新型运载系统的情况下摧毁数百或数千枚核武装远程弹道导弹或其弹头。

Because such a defense is technologically and financially infeasible , some experts have instead advocated deploying systems to defend the United States against a smaller attack .

由于这种防御在技术和经济上都是不可行的，因此一些专家转而主张部署系统来保护美国免受较小规模的攻击。

Examples include a full-scale attack by an emerging ballistic missile state such as North Korea, a purely accidental launch or an unauthorized attack by missiles from North Korea, Russia, or China, a limited raid intended to coerce the United States, or a ragged retaliation.

例子包括朝鲜等新兴弹道导弹国家的全面攻击，朝鲜、俄罗斯或中国的导弹纯粹意外发射或未经授权的攻击，旨在胁迫美国的有限袭击，或粗暴的报复。

Such systems would be much smaller and less capable than the system proposed in the Golden Dome executive order .

此类系统将比金顶行政命令中提议的系统小得多，能力也低得多。

The size of a smaller attack would depend on its purpose.

较小攻击的规模取决于其目的。

North Korea may soon be able to launch an attack with 20 intercontinental ballistic missiles having multiple warheads, accompanied by sophisticated countermeasures.

朝鲜可能很快就能用 20 枚多弹头洲际弹道导弹发动攻击，并辅以复杂的反制措施。

An unauthorized attack by a Russian submarine could launch 16 ballistic missiles carrying about 100 warheads, and a limited coercive strike by Russia or China could have a dozen ballistic missiles carrying 60 warheads .

俄罗斯潜艇未经授权的攻击可能会发射16枚携带约100枚弹头的弹道导弹，而俄罗斯或中国的有限强制攻击可能会发射12枚携带60枚弹头的弹道导弹。

A single missile launched accidentally by Russia, China, or North Korea could carry five to 10 warheads.

俄罗斯、中国或朝鲜意外发射的一枚导弹可能携带 5 到 10 枚弹头。

Defending against such attacks could require disabling or destroying a dozen or more ballistic missiles and tens of warheads accompanied by sophisticated countermeasures.

防御此类攻击可能需要禁用或摧毁十几枚或更多弹道导弹和数十枚弹头，并采取复杂的对抗措施。

Although details of the Golden Dome are still unclear and largely secret more than a year after it was announced, its leaders have now said it will focus first on defending against a strike by nuclear-armed long-range ballistic missiles on United States leaders or a strike by an emerging ballistic missile state against its territory.

尽管“金顶”计划的细节在宣布一年多后仍不清楚，而且在很大程度上是保密的，但其领导人现在表示，它将首先集中于防御核武装远程弹道导弹对美国领导人的袭击，或新兴弹道导弹国家对其领土的袭击。

We focus here on these goals.

我们在这里重点关注这些目标。

Even with planned improvements, the current ground-based midcourse defense system is not expected to provide a robust or reliable defense against more than a small number of ballistic missiles equipped with simple countermeasures for the next 15 years.

即使按计划进行改进，目前的陆基中段防御系统预计在未来 15 年内也只能对少数配备简单对抗措施的弹道导弹提供强大或可靠的防御。

Other U.S. land- and sea-based missile defense systems were not designed to defend against nuclear-armed intercontinental ballistic missiles, and it is unclear when if ever they could work against even a small number of them.

美国其他陆基和海基导弹防御系统并不是为了防御核洲际弹道导弹而设计的，目前还不清楚它们何时能够对抗哪怕是一小部分导弹。

Space-based boost-phase interceptors would not make up for these deficiencies.

天基助推段拦截弹无法弥补这些缺陷。

Instead, they would add a hugely expensive, complex, ineffective, and destabilizing layer to the system.

相反，他们会在系统中添加一个极其昂贵、复杂、低效且不稳定的层。

Because it is likely to provoke responses that increase the danger to the United States, the space-based interceptor program should be canceled now.

由于它可能会引发增加美国危险的反应，因此现在应该取消天基拦截器计划。

Rather than spending billions of dollars on terrestrial strategic missile defense layers that have little chance of protecting against even a limited attack by long-range ballistic missiles, let alone the hundreds or thousands of missiles and even more warheads in a large-scale attack, the United States should instead focus its resources and attention on reducing the threat of nuclear weapons using risk reduction strategies and arms control agreements.

美国不应该花费数十亿美元建设地面战略导弹防御层，因为即使是有限的远程弹道导弹攻击也几乎无法防御，更不用说大规模攻击中的数百或数千枚导弹甚至更多弹头，美国应该将其资源和注意力集中在利用风险降低战略和军备控制协议来减少核武器威胁上。

Difficult as such agreements are to negotiate, they have been the only historically successful approach to reducing the nuclear threat to the United States.

尽管此类协议的谈判很困难，但它们是历史上唯一成功减少美国核威胁的方法。

The Fundamental Problems A successful strategic missile defense would have to disable or destroy attacking missiles or warheads during one or more of the three phases of flight .

基本问题 成功的战略导弹防御必须在三个飞行阶段中的一个或多个阶段禁用或摧毁攻击导弹或弹头。

During a missile’s boost phase, its rocket motor is burning, it is accelerating, and its warheads have not yet been deployed.

在导弹的助推阶段，火箭发动机正在燃烧，正在加速，弹头尚未部署。

This phase lasts for less than three minutes for modern, solid-propellant ballistic missiles.

对于现代固体推进剂弹道导弹来说，这个阶段持续不到三分钟。

The midcourse phase begins once the missile’s warheads have been deployed.

导弹弹头部署完毕后，中段阶段就开始了。

A missile could deploy its warheads and countermeasures, such as decoy warheads, within seconds.

导弹可以在几秒钟内部署其弹头和对抗措施，例如诱饵弹头。

These then travel together through space on ballistic trajectories for 30 to 45 minutes.

然后它们沿着弹道轨迹一起在太空中飞行 30 到 45 分钟。

The terminal phase begins when warheads start to re-enter the atmosphere and lasts about 30 seconds.

当弹头开始重新进入大气层时，最后阶段开始，持续约 30 秒。

Each of these phases poses a different challenge for missile defense.

每个阶段都对导弹防御提出了不同的挑战。

Boost-phase defense is a race against time and distance.

助推阶段防御是一场与时间和距离的赛跑。

Midcourse defense is a battle to discriminate warheads from decoys and overcome other countermeasures.

中段防御是一场区分弹头和诱饵并克服其他对抗措施的战斗。

Terminal defenses face very short engagement times and can at best defend only small areas.

末端防御的交战时间非常短，最多只能防御小区域。

Existing terminal missile defense systems, such as the Terminal High Altitude Area Defense, were not designed to defend against intercontinental-range ballistic missiles , are too slow to engage them except near their target , and could be defeated by penetration aids .

现有的末端导弹防御系统，例如末端高空区域防御系统，并不是为防御洲际弹道导弹而设计的，除了靠近目标之外，其攻击速度太慢，并且可能被渗透辅助设备击败。

The war in the Middle East has shown that even firing several of these exquisite interceptors at each medium-range ballistic missile does not ensure interception.

中东战争表明，即使向每枚中程弹道导弹发射数枚这种精巧的拦截器也不能确保拦截。

These expensive systems would not be able to successfully defend the United States against a limited attack by nuclear-armed strategic missiles.

这些昂贵的系统无法成功保护美国免受核战略导弹的有限攻击。

They would have to be significantly upgraded even to be tested in such a role, an effort that would take a decade or more.

即使要接受这样的角色测试，它们也必须进行显着升级，而这将需要十年或更长时间。

Developing cheaper and more capable new systems would take even longer, if it is even possible.

如果可能的话，开发更便宜、功能更强大的新系统将需要更长的时间。

Scores of such systems would be required to attempt to defend only selected leadership and command and control sites, strategic infrastructure, and population centers against even a limited attack.

需要数十个此类系统来尝试仅保护选定的领导和指挥控制站点、战略基础设施和人口中心免受哪怕是有限的攻击。

The Aegis Standard Missile 3 Block IIA midcourse-intercept system was designed for regional defense against medium- and intermediate-range missiles , not defense of the United States against nuclear-armed strategic missiles.

宙斯盾标准导弹 3 Block IIA 中程拦截系统旨在针对中程和中程导弹进行区域防御，而不是针对美国的核战略导弹防御。

Its 2020 intercontinental ballistic missile-class intercept was a scripted developmental demonstration against a simple target under favorable conditions, not an operationally realistic test against long-range, nuclear-armed missiles using decoys, penetration aids, multiple warheads, salvo launches, or modern intercontinental missile trajectories.

其2020年洲际弹道导弹级拦截是在有利条件下针对简单目标进行的有脚本的开发演示，而不是针对使用诱饵、突防辅助装置、多弹头、齐射或现代洲际导弹弹道的远程核武装导弹进行的实际作战测试。

To defend the United States against even limited intercontinental ballistic missile attacks, this system would have to be significantly upgraded and tested, which would take a decade or more.

为了保护美国免受哪怕是有限的洲际弹道导弹攻击，该系统必须进行重大升级和测试，这将需要十年或更长时间。

Even then, it would face the still unsolved technical challenge of discriminating decoys from warheads .

即便如此，它仍将面临区分诱饵和弹头的技术挑战。

The small number of tests of the Ground-based Midcourse Defense system have been scripted and designed for success, and have not considered realistic attacks with multiple warheads, sophisticated decoys and other countermeasures, or attacks on the system’s sensors.

陆基中段防御系统的少量测试是为了成功而编写和设计的，并没有考虑使用多弹头、复杂诱饵和其他对抗措施的实际攻击，或对系统传感器的攻击。

This system has yet to demonstrate a solution to the technical challenge of discriminating decoys from warheads.

该系统尚未证明能够解决区分诱饵和弹头的技术挑战。

Even in the absence of complex countermeasures, the current system is assessed to have only some capability against a very limited attack.

即使在没有复杂的对策的情况下，当前系统也被评估为仅具有一定的能力来应对非常有限的攻击。

To reduce costs, Space Force General Michael Guetlein, who leads Golden Dome, has advocated building directed-energy weapons .

为了降低成本，金顶太空部队将军迈克尔·盖特兰（Michael Guetlein）主张建造定向能武器。

But developing and deploying directed-energy weapons with the power, beam focusing, tracking, dwell time, and durability required for a weapon that would be useful against intercontinental-range ballistic missiles or nuclear warheads would take decades , if such weapons are feasible.

但是，如果这种武器可行的话，开发和部署具有可用于对抗洲际弹道导弹或核弹头的武器所需的功率、波束聚焦、跟踪、停留时间和耐用性的定向能武器将需要数十年的时间。

The unsolved deficiencies of existing midcourse and terminal defense systems appear to be the main motivations for including space-based interceptors in the Golden Dome proposal.

现有中段和末端防御系统尚未解决的缺陷似乎是将天基拦截器纳入金圆顶提案的主要动机。

Space-based boost-phase defense has been abandoned many times because of insurmountable challenges .

天基助推段防御因难以克服的挑战而多次被放弃。

But space-based interceptors have now entered prototype development, and are slated for flight demonstrations in 2027 and integration into the Golden Dome architecture by 2028 .

但天基拦截弹现已进入原型开发阶段，预计于 2027 年进行飞行演示，并于 2028 年集成到金顶架构中。

Contracts worth up to $3.2 billion that mandate on-orbit tests by 2028 have been awarded to 12 firms.

12 家公司已获得价值高达 32 亿美元的合同，要求在 2028 年之前进行在轨测试。

The program has identified a need for interceptors that would attack missiles during their boost phase, would disable or destroy warheads during their midcourse phase, or attack hypersonic-glide vehicles within the atmosphere.

该计划已经确定需要拦截器，这些拦截器可以在助推阶段攻击导弹，在中段阶段禁用或摧毁弹头，或者攻击大气层内的高超音速滑翔飞行器。

With midcourse discrimination unsolved and no effective terminal strategic defenses in existence, boost-phase defense is often presented as a better way to prevent the warheads of long-range ballistic missiles from striking their targets, because the booster is relatively large and its exhaust plume is bright and easy to see.

由于中段歧视尚未解决且不存在有效的末端战略防御，助推阶段防御通常被认为是防止远程弹道导弹弹头打击目标的更好方法，因为助推器相对较大，其排气羽流明亮且易于看到。

Hit the missile early, the argument goes, and you might be able to prevent its warheads and decoys from ever being deployed.

这种观点认为，尽早击中导弹，也许就能阻止其弹头和诱饵的部署。

But intercepting a missile during its boost phase is not easy .

但拦截处于助推阶段的导弹并不容易。

The technology required to home on and collide with a cold missile body near or inside a bright exhaust plume has not yet been demonstrated .

追踪明亮废气羽流附近或内部的冷导弹弹体并与之碰撞所需的技术尚未得到证实。

In addition, the attacker can employ decoy rockets and other countermeasures to confuse or overwhelm attempts at boost-phase intercept.

此外，攻击者还可以使用诱饵火箭和其他对抗措施来迷惑或压倒助推阶段拦截的尝试。

But the most challenging aspect of boost-phase defense is the very short time available for intercept.

但助推阶段防御最具挑战性的方面是可用于拦截的时间非常短。

Everything the boost-phase defense must do — detect the launch of a missile, compute its initial trajectory, decide whether it is a threat, and if it is, fire interceptors that are fast enough to reach and collide with the accelerating and maneuvering missile — all this must happen before the attacking missile’s motor shuts down.

助推阶段防御必须做的一切——检测导弹的发射，计算其初始轨迹，确定它是否是威胁，如果是，则发射足够快的拦截器以到达加速和机动导弹并与其相撞——所有这些都必须在攻击导弹的发动机关闭之前发生。

The resulting time pressure is extreme.

由此产生的时间压力是极大的。

The full burn times of most modern intercontinental ballistic missiles and submarine-launched ballistic missiles are already short, typically three minutes or less.

大多数现代洲际弹道导弹和潜射弹道导弹的完全燃烧时间已经很短，通常为三分钟或更短。

They can be made even shorter , and the missiles don’t need to use their full burn times to deliver their warheads to many targets in the United States.

它们可以做得更短，而且导弹不需要利用其完整的燃烧时间来将弹头发射到美国的许多目标。

Furthermore, new missiles are being designed with even shorter full burn times .

此外，新导弹的设计完全燃烧时间甚至更短。

The full burn time of North Korea’s Hwasong-18 intercontinental ballistic missile is about 170 seconds, but it would only need to burn for about 158 seconds for its warhead to strike Seattle and only about 137 seconds to strike Fairbanks .

朝鲜的火星18洲际弹道导弹的完全燃烧时间约为170秒，但其弹头只需燃烧约158秒即可攻击西雅图，攻击费尔班克斯只需约137秒。

Russia’s RS-24 Yars intercontinental ballistic missile would need to burn for only about 150 seconds to strike Seattle or Boston from the closest Russian missile garrisons or silo fields and only about 145 seconds to strike Fairbanks .

俄罗斯的RS-24亚尔斯洲际弹道导弹只需燃烧约150秒，即可从最近的俄罗斯导弹驻地或发射井袭击西雅图或波士顿，只需约145秒即可袭击费尔班克斯。

(We follow the 2003 American Physical Society , 2012 National Research Council , and 2025 American Physical Society reports in using their solid-propellant intercontinental ballistic missile computer model S1 to estimate burn times.)

（我们遵循 2003 年美国物理学会、2012 年国家研究委员会和 2025 年美国物理学会的报告，使用他们的固体推进剂洲际弹道导弹计算机模型 S1 来估计燃烧时间。）

A modern solid-propellant ballistic missile cannot be reliably detected by infrared space sensors until it rises above any clouds over the launch site, which typically takes about 30 seconds .

现代固体推进弹道导弹只有升到发射场上空的云层上方才能被红外空间传感器可靠地探测到，这一过程通常需要大约 30 秒。

Computing its trajectory with sufficient accuracy to generate an interceptor firing solution takes another 15 seconds or so .

以足够的精度计算其轨迹以生成拦截弹发射解决方案还需要 15 秒左右的时间。

To gather the information needed to decide whether to fire interceptors — in particular determining whether the missile is a short- or medium-range ballistic missile or space launch vehicle, or an intercontinental ballistic missile or submarine-launched ballistic missile on an attack (not a test) trajectory — takes a further 30 seconds or more .

为了收集决定是否发射拦截弹所需的信息，特别是确定导弹是短程还是中程弹道导弹或太空运载火箭，还是洲际弹道导弹或攻击（而非测试）轨迹上的潜射弹道导弹，还需要 30 秒或更长时间。

Only then — at least 75 seconds after launch — can the defender confidently fire interceptors.

只有这样——发射后至少 75 秒——防御者才能自信地发射拦截弹。

For the examples just given, the interceptors would have only 45 to 75 seconds to fly out and strike the accelerating and maneuvering missile before it deploys its warheads.

对于刚才给出的例子，拦截器只有 45 到 75 秒的时间飞出并在加速和机动导弹部署弹头之前对其进行攻击。

The decision time would be only a few tens of seconds, increasing the risk of serious mistakes in a crisis and accidental escalation to nuclear war.

决策时间只有几十秒，增加了危机中出现严重错误以及意外升级为核战争的风险。

But the time constraint is likely to be even more brutal.

但时间限制可能更加残酷。

Even today, a submarine-launched ballistic missile launched from Arctic, Atlantic, or Pacific waters could strike an American city after burning for only about 100 seconds.

即使在今天，从北极、大西洋或太平洋水域发射的潜射弹道导弹也能在燃烧约 100 秒后击中美国城市。

And Russia is reportedly developing a “Yars-M” variant that deploys multiple “reentry” vehicles , each with its own rocket motor and guidance.

据报道，俄罗斯正在开发一种“Yars-M”变体，可部署多个“再入”飞行器，每个飞行器都有自己的火箭发动机和制导装置。

These would separate from the second stage only about 100 seconds after launch.

发射后仅约 100 秒，它们就会与第二级分离。

A boost-phase defense would have to intercept the missile before then or face a more challenging “many targets” problem.

助推阶段防御必须在此之前拦截导弹，否则将面临更具挑战性的“多目标”问题。

In these situations, interceptors would have only 25 seconds to reach the missile, a practical impossibility.

在这种情况下，拦截器只有 25 秒的时间才能到达导弹，这实际上是不可能的。

Adversaries could deploy fast-burn ballistic missiles with even shorter full-burn times to defeat the system.

对手可以部署完全燃烧时间更短的快速燃烧弹道导弹来击败该系统。

The 2012 National Research Council report used a burn time of 150 seconds for reference.

2012年国家研究委员会的报告使用了150秒的燃烧时间作为参考。

The 2003 American Physical Society study constructed an intercontinental ballistic missile model (its solid-propellant missile S3) having a full burn time of only 130 seconds.

2003年美国物理学会的研究构建了一种洲际弹道导弹模型（其固体推进剂导弹S3），其完全燃烧时间仅为130秒。

And a 1985 Office of Technology Assessment report found that an MX-sized intercontinental ballistic missile could be designed to burn out in less than 60 seconds, and described a design with a full burn time of 50 seconds.

1985 年技术评估办公室的一份报告发现，MX 尺寸的洲际弹道导弹可以在 60 秒内燃尽，并描述了完全燃烧时间为 50 秒的设计。

It would not require new technology to substantially shorten the burn time.

不需要新技术来大幅缩短燃烧时间。

Building a boost-phase defense would create a strong incentive for U.S. adversaries to deploy “fast burn” ballistic missiles, launch them from closer to U.S. cities, fly them on faster, depressed trajectories, and design them to be harder to intercept.

建立助推级防御系统将强烈激励美国对手部署“快速燃烧”弹道导弹，从距离美国城市较近的地方发射导弹，以更快、低速的轨迹飞行，并将其设计得更难以拦截。

Assuming they will not do this would be a classic example of “the fallacy of the last move.”

假设他们不会这样做，这将是“最后一步的谬误”的典型例子。

How can a boost-phase defense have any chance of reaching attacking ballistic missiles within such short interception windows?

助推阶段防御如何有机会在如此短的拦截窗口内到达攻击弹道导弹？

It is only possible if the system’s interceptors are based very close to the boost-phase trajectories of the missiles they will seek to defend against, which requires basing them in space.

只有当系统的拦截器非常接近它们要防御的导弹的助推阶段弹道时，才有可能实现这一点，这需要将它们部署在太空中。

However, there is a fundamental problem with basing interceptors in space: they are almost never where you need them to be .

然而，在太空中部署拦截弹存在一个根本问题：它们几乎永远不在你需要的地方。

The reason is that to remain in space, space-based interceptors must orbit Earth , and Earth rotates underneath their orbits .

原因是为了留在太空中，天基拦截器必须绕地球运行，而地球则在其轨道下旋转。

When a threatening missile is launched, most interceptors are too far from the attacking missile’s boost-phase trajectory to reach the missile before it deploys its warhead(s).

当发射威胁导弹时，大多数拦截器距离攻击导弹的助推阶段弹道太远，无法在导弹部署弹头之前到达导弹。

This is the “absentee” problem, and it’s why huge constellations of space-based interceptors are needed even to counter a limited attack.

这就是“缺席”问题，这就是为什么即使是为了反击有限的攻击也需要大量的天基拦截器。

How huge?

有多大？

Well, calculations using the well-verified analytical framework developed by the 2003 American Physical Society study (which was also used by the 2012 National Research Council study , the 2025 American Physical Society study , and Wright 2026 ) indicate tens of thousands: Defending the lower 48 states against just four solid-propellant intercontinental ballistic missiles launched within about 200 seconds from the same area of North Korea, or from the same missile garrison or silo field in northern Russia (and preventing spoofing of the defensive system), would require a constellation of about 24,000 space-based interceptors with 5g accelerations and burnout speeds of five kilometers per second.

好吧，使用 2003 年美国物理学会研究（2012 年国家研究委员会研究、2025 年美国物理学会研究和赖特 2026 年研究也使用了该研究）开发的经过充分验证的分析框架进行的计算表明，有数以万计的结果：保卫美国本土 48 个州免受在大约 200 秒内从朝鲜同一地区或同一导弹驻地或同一基地发射的四枚固体推进剂洲际弹道导弹的攻击。俄罗斯北部的筒仓场（并防止防御系统被欺骗），将需要大约 24,000 个天基拦截器组成的星座，其加速度为 5g，燃尽速度为每秒 5 公里。

This assumes only one interceptor is assigned to each attacking missile, and that no attempt is made to defend cities in Alaska.

这是假设每枚攻击导弹只分配了一个拦截器，并且没有尝试保卫阿拉斯加的城市。

Russia has practiced launching its submarine-launched ballistic missiles in salvos since 1991, when it launched 16 only a few seconds apart from a submerged submarine.

俄罗斯自1991年起就开始练习齐射潜射弹道导弹，当时俄罗斯发射的16枚弹道导弹与一艘水下潜艇的间隔仅几秒钟。

It has continued to practice two- and four-missile salvos .

它继续练习两枚和四枚导弹齐射。

To defend the lower 48 states against a salvo of even 10 such missiles would require a constellation of at least 60,000 such space-based interceptors.

为了保卫美国本土 48 个州免受哪怕 10 枚此类导弹的齐射，也需要至少 60,000 个此类天基拦截弹。

A reliable, resilient space-based system would require many more interceptors.

一个可靠、有弹性的天基系统需要更多的拦截器。

Failing to intercept even a single inbound missile would be a catastrophe.

即使无法拦截一枚来袭导弹也将是一场灾难。

Expecting interceptors to work perfectly after being exposed to the harsh environment of space for several years without servicing would invite failure.

如果拦截器在恶劣的太空环境中暴露数年而没有维修，仍然能够完美工作，就会导致失败。

In the recent conflict with Iran, Israel and the United States have typically fired two to five highly capable interceptor missiles at every incoming Iranian missile, even though the Iranian missiles are much less capable than intercontinental or submarine-launched ballistic missiles.

在最近与伊朗的冲突中，以色列和美国通常会向每一枚来袭的伊朗导弹发射两到五枚高性能拦截导弹，尽管伊朗导弹的能力远低于洲际或潜射弹道导弹。

Similarly, Ukraine typically fired two to four highly capable interceptor missiles at every incoming Russian missile until its supply of interceptors ran low.

同样，乌克兰通常会向每一枚来袭的俄罗斯导弹发射两到四枚高性能拦截导弹，直到其拦截弹供应不足。

Ukraine then began firing only one , which led to many attacking missiles getting through to their targets.

随后乌克兰开始只发射一枚，这导致许多攻击导弹击中了目标。

Increasing the probability of success by firing three space-based interceptors at each target missile in the previous example would require 180,000 space-based interceptors.

在前面的例子中，通过向每枚目标导弹发射三枚天基拦截器来提高成功概率将需要 180,000 个天基拦截器。

Increasing the acceleration and speed of the interceptors in the constellation could in principle greatly reduce the number required, but at great cost.

原则上，增加星座中拦截弹的加速度和速度可以大大减少所需的数量，但成本很高。

Extremely high-acceleration 10 kilometers per second interceptors, for example, would each be tens of times more massive , with a corresponding increase in cost.

例如，每秒 10 公里的极高加速度拦截弹的质量将增加数十倍，成本也会相应增加。

And the consequences of a failure or an attack on such a system — which would have a much smaller number of much higher-value interceptors — would be far more serious.

这种系统的故障或攻击（其拦截器的数量要少得多，但价值更高）的后果将会严重得多。

With many fewer interceptors, clusters, or garages, each loss would degrade the system faster and give the attacker a larger window to launch its ballistic missiles without risk of intercept.

由于拦截器、集群或车库数量较少，每次损失都会使系统更快地退化，并为攻击者提供更大的窗口来发射弹道导弹，而无需担心被拦截的风险。

A recent Congressional Budget Office report estimated the expected cost of the strategic missile defense component of a Golden Dome system at about $1.2 trillion.

美国国会预算办公室最近的一份报告估计，金顶系统的战略导弹防御部分的预期成本约为 1.2 万亿美元。

Despite requests, the Department of Defense did not provide information about its planned Golden Dome architecture.

尽管提出要求，国防部并未提供有关其计划中的金顶建筑的信息。

The budget office, therefore assessed the costs of a much more limited system that could be multiplied to approximately estimate Golden Dome’s full cost.

因此，预算办公室评估了一个更加有限的系统的成本，可以将其乘以近似估计金顶的全部成本。

The costs listed in the report are accordingly vastly smaller than likely for a system like Golden Dome.

因此，报告中列出的成本远低于金顶这样的系统的成本。

The report also dramatically underestimated the number of system elements that would be required for the modules to be effective.

该报告还大大低估了模块发挥作用所需的系统元素数量。

For example, it estimated that 7,800 space-based interceptors would be needed to defend against one salvo of 10 missiles, assigning two interceptors to each attacking missile, but the report did not state its other assumptions.

例如，报告估计需要7,800枚天基拦截器来防御10枚导弹的齐射，为每枚攻击导弹分配两枚拦截器，但报告没有说明其他假设。

One can arrive at such a small number only by making very unrealistic assumptions: for example, that the interceptors are fired with zero decision time and have very high accelerations and terminal velocities, and that the attacking missiles use only very old technology.

只有做出非常不切实际的假设才能得出这么小的数字：例如，拦截弹的发射决策时间为零，并且具有非常高的加速度和终端速度，而攻击导弹仅使用非常古老的技术。

But firing interceptors with zero decision time would make the system vulnerable to spoofing and mistakes.

但以零决策时间发射拦截器将使系统容易受到欺骗和错误。

Using interceptors with very high accelerations and terminal velocities would make them heavy and expensive, and the system more vulnerable to attack.

使用加速度和终端速度非常高的拦截器会使它们变得笨重且昂贵，并且系统更容易受到攻击。

And assuming attacking missiles use only very old technology is unrealistic.

假设攻击导弹仅使用非常古老的技术是不现实的。

These facts make clear that creating a robust, space-based system that is only capable of defending the United States in principle against a very limited attack would cost trillions of dollars over 20 years.

这些事实清楚地表明，创建一个原则上只能保护美国免受非常有限的攻击的强大天基系统将在 20 年内花费数万亿美元。

A comprehensive defense would cost much, much more.

全面防御的成本要高得多。

Given the stakes, an adversary has every incentive to design attacks and deploy technologies to confuse, overwhelm, or otherwise defeat the defensive system of its opponent.

考虑到风险，对手完全有动机设计攻击并部署技术来迷惑、压倒或以其他方式击败对手的防御系统。

Launching a salvo of ballistic missiles to overwhelm the defense is one such tactic.

发射弹道导弹齐射来压倒防御就是一种这样的策略。

An adversary could also overwhelm the defense with an intercontinental ballistic missile that has only two stages that burn out quickly and then deploys many reentry vehicles, each with its own motor and guidance system, a missile like the “Yars-M” missile Russia is already developing .

对手还可以用洲际弹道导弹压倒防御，这种导弹只有两级，很快就会烧毁，然后部署许多再入飞行器，每个飞行器都有自己的发动机和制导系统，就像俄罗斯已经在开发的“亚尔斯-M”导弹一样。

Or it could launch a salvo of smaller, less expensive missiles to trick the defense and exhaust its supply of interceptors; fire rocket-propelled decoys, flares, and jammers during the flight of the missile’s upper stages to confuse the defense and deplete its interceptors; have upper stages execute evasive maneuvers while at the same time releasing decoys; and deploy reentry vehicles before the final stage burns out .

或者它可以发射一系列更小、更便宜的导弹来欺骗防御并耗尽拦截弹的供应；在导弹上级飞行期间发射火箭推进的诱饵、照明弹和干扰器，以迷惑防御并耗尽其拦截器；让上级执行规避动作，同时释放诱饵；并在最后一级烧毁之前部署再入飞行器。

These measures would push requirements beyond those calculated above, and any boost-phase defense program would need a credible plan to deal with them.

这些措施将使需求超出上述计算范围，任何推进阶段的防御计划都需要一个可靠的计划来应对这些需求。

An adversary could also attack the defensive system and its sensors directly , using anti-satellite weapons.

对手还可以使用反卫星武器直接攻击防御系统及其传感器。

Even successfully intercepting a direct-ascent anti-satellite weapon would cost the system an interceptor.

即使成功拦截直升式反卫星武器，系统也会损失拦截器。

Alternatively, an adversary could explode nuclear weapons in space or salvage fuze their reentry vehicles so they detonate when an interceptor strikes them.

或者，对手可以在太空中引爆核武器，或者回收其再入飞行器的引信，以便在拦截器击中它们时引爆。

This would damage the defensive system’s sensors and electronics or overwhelm or confuse them, making it difficult or impossible for the system to home on other targets.

这会损坏防御系统的传感器和电子设备，或者淹没或迷惑它们，使系统很难或不可能瞄准其他目标。

There is no prospect of deploying a missile defense system within the next 15 years that could reliably protect against even a limited but effective raid intended to coerce the United States, let alone a substantial attack by an emerging ballistic missile state such as North Korea or a major attack by Russia or China.

在未来15年内部署能够可靠地抵御旨在胁迫美国的有限但有效的袭击的导弹防御系统是不可能的，更不用说朝鲜等新兴弹道导弹国家的大规模攻击或俄罗斯或中国的重大攻击了。

Current ground-based systems struggle against even relatively small and unsophisticated missile threats.

当前的地面系统甚至可以应对相对较小且不复杂的导弹威胁。

Increasing the number of interceptors (or kill vehicles) to attempt to address more sophisticated missile threats, including more sophisticated countermeasures, would be costly and unlikely to stay ahead of the offensive capability.

增加拦截器（或杀伤器）的数量来试图应对更复杂的导弹威胁，包括更复杂的对抗措施，成本高昂，而且不太可能保持领先于进攻能力。

Space-based interceptors will not solve this problem, given their extremely unfavorable cost-exchange ratio and the many straightforward countermeasures an adversary could use.

天基拦截弹无法解决这个问题，因为它们的成本交换比极其不利，而且对手可以使用许多直接的对策。

The conclusion of the 2012 National Research Council study that the United States should not invest any more money or resources in systems for boost-phase missile defense remains valid.

2012 年国家研究委员会的研究结论认为，美国不应在助推级导弹防御系统上投入更多资金或资源，这一结论仍然有效。

We therefore recommend that the proposed space-based interceptor program be canceled.

因此，我们建议取消拟议的天基拦截器计划。

We also assess that midcourse intercept is and will remain ineffective against limited but sophisticated missile attacks.

我们还评估，中段拦截对于有限但复杂的导弹攻击来说仍然无效。

The United States should shift resources and attention to diplomatic efforts to reduce the nuclear threat, the only approach that has been successful in the past.

美国应该将资源和注意力转移到减少核威胁的外交努力上，这是过去唯一成功的方法。

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.

弗雷德里克·兰姆 (Frederick Lamb) 是伊利诺伊大学理论天体物理学荣休布兰德和莫妮卡·福特纳主席，也是军备控制和国内和国际安全项目的核心教员。

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.

他共同主持了美国物理学会2003年助推段导弹防御研究，并主持了2025年战略弹道导弹防御研究。

He is a member of the American Academy of Arts and Sciences and a fellow of the American Physical Society.

他是美国艺术与科学学院院士和美国物理学会会员。

Laura Grego, Ph.D., is a senior scientist and the research director in the Global Security Program at the Union of Concerned Scientists.

劳拉·格雷戈博士是一位资深科学家，也是忧思科学家联盟全球安全项目的研究主任。

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.

她是美国物理学会会员，共同主持了该学会 2025 年战略弹道导弹防御研究，并于 2023 年荣获利奥·西拉德讲座奖。