A national missile defense system, or Golden Dome, proposed by the Trump administration would cost $1.2 trillion to build and maintain over the next 20 years, the Congressional Budget Office estimated in a cost-projection analysis released Tuesday.
Acquisition costs would total just over $1 trillion, said the CBO, a nonpartisan federal agency that provides budgetary analyses for Congress. The estimate is significantly more than the $185 billion the Trump administration set aside for the project in its proposed fiscal 2027 defense budget.
That gap is due, at least in part, to the fact that there are no publicly available plans from the White House nor the Pentagon about what the system will look like, “making it impossible to estimate the long-term cost of the GDA system being contemplated by DoD,” per the report.
“DoD’s stated cost appears to cover a shorter time frame than CBO’s analysis and may reflect a different scope of activities and budget categories,” the report continues. “Even so, that stated cost is far lower than CBO’s estimate for a notional NMD [national missile defense] architecture consistent with the ‘Iron Dome’ executive order.
“That difference suggests either that GDA’s objective architecture is more limited than CBO’s notional NMD system or that DoD expects significant funding from other accounts to contribute to GDA (or both).”
The CBO based its estimate on a four-tiered defense system: a space-based layer, upper- and lower-level surface interceptor layers and multiple spread out surface interceptors, which would provide protection for all of the continental U.S. plus Alaska and Hawaii.
This proposed system would be able to defend against multiple missiles fired simultaneously and would protect against threats from hypersonics, ballistics and cruise missiles.
But the system could not successfully engage with a large-scale attack from a peer or near-peer adversary like Russia or China, according to the report.
As the cost estimate is based on the desired capabilities laid out in a January 2025 executive order, it doesn’t include funding for research and development of future technologies, nor does it take into account ground forces or a communication system necessary to make the proposed system work.
The report also notes that the project may face delays due to the need to replenish the nation’s stockpile of THAAD and Patriot interceptor missiles, as well as radar systems, a great number of which have been deployed in the war on Iran.
Other potential roadblocks include Pentagon funding constraints, plus the training necessary to deploy the system, the CBO said.
Some lawmakers have already expressed their concern over the proposed cost.
“The president’s so-called ‘Golden Dome’ is nothing more than a massive giveaway to defense contractors paid for entirely by working Americans,” Sen. Jeff Merkley, D-Ore., who requested the CBO estimate, said in a statement. “It will do little to advance American national security.”