Golden Dome’s cost: anywhere from billions to trillions, depending on design

WASHINGTON — A new report estimates the Golden Dome missile defense program could cost anywhere from $252 billion to $3.6 trillion over 20 years — depending on which threats it counters and where it provides coverage. The vast range underscores how many questions remain unanswered eight months after Trump announced the initiative, according to a study published Sept. 12 by the American Enterprise Institute.

“In the end, Golden Dome’s cost will not be determined by fiscal constraints or technical capabilities, but by political choices: which risks leaders are willing to mitigate, which they are willing to trade, and which they are prepared to accept,” writes Todd Harrison, AEI senior fellow and author of the 51-page report. “As long as requirements remain undefined, Golden Dome can cost as much or as little as policymakers are willing to spend.”

The report, Build Your Own Golden Dome: A Framework for Understanding Costs, Choices, and Tradeoffs, is the first comprehensive cost estimate for the program, examining options from drone defenses to space-based interceptors.

With no official architecture released, Harrison built cost models for individual components and combined them in different ways to create six example architectures. He concludes that even modest shifts in objectives can drive costs sharply upward, with space-based interceptors the biggest factor by far.

Harrison says Trump’s cited $175 billion price tag would buy only a limited system, inadequate against the scale of China’s and Russia’s arsenals.

What is Golden Dome?

Trump announced Golden Dome in January through an executive order directing the Defense Department to develop a comprehensive homeland air and missile defense system. The order calls for protecting the United States “against ballistic, hypersonic, advanced cruise missiles, and other next-generation aerial attacks from peer, near-peer, and rogue adversaries.”

Golden Dome is envisioned as a “system of systems,” integrating current and future capabilities across multiple defense layers—from ground-based interceptors to space-based assets.

Harrison’s analysis outlines six example architectures, ranging from limited tactical defense to a comprehensive shield. The cost variations are dramatic:

• Architecture 4 (Limited Tactical Defense): $252 billion — focused on drone swarms and cruise missiles.
• Architecture 1 (Accelerated Homeland Defense): $471 billion — designed to show progress within Trump’s timeline while staying within his $175 billion target for the first five years.
• Architecture 6 (Robust All-Threat Defense): $3.6 trillion — aimed at providing protection against all threat types.
• Systems relying heavily on space-based interceptors, like the $2.4 trillion “Space-centric Strategic Defense” architecture, cost far more than ground-based alternatives.

Major unanswered questions

Geographic Coverage: It is unclear whether Golden Dome will protect only the continental United States, Hawaii, and Alaska, or also cover U.S. territories, overseas bases, and allies. Trump has discussed making Canada a partner, but no other allies are mentioned.

Threat Scope: The executive order lists a broad range of threats but does not define the scale—whether to counter small rogue launches or full-scale assaults from Russia and China.

Technical Requirements: Parameters such as required effectiveness, system resilience, and acceptable risk remain undefined.

The study cites Defense Intelligence Agency estimates that China and Russia could field more than 16,000 missiles against the U.S. homeland by 2035 — though Harrison calls such long-term projections “debatable.”

The analysis avoids endorsing specific architectures, instead emphasizing that Golden Dome’s ultimate cost will hinge on political choices about risk tolerance, not technical constraints.

“At the core of understanding Golden Dome’s cost lies a deceptively simple yet intractable question,” Harrison writes. “How much homeland air and missile defense is enough? No architecture can deliver total protection from every threat, and Golden Dome’s cost depends on its ambition.”