Trump wants a system that can defend against a wide array of enemy weapons — from intercontinental ballistic missiles to hypersonic and cruise missiles to drones — and he wants it ready in about three years, or as he nears the end of his second term in office.

Four months after Trump initially ordered the Pentagon to develop options for the system, however, little in the way of further details has emerged.

“The main challenges will be cost, the defense industrial base, and political will. They can all be overcome, but it will take focus and prioritization,” said Melanie Marlowe, a nonresident senior associate in the Missile Defense Project at Washington’s Center for Strategic and International Studies.

“The White House and Congress are going to have to agree on how much to spend and where the money will come from,” Marlowe said, noting that “our defense industrial base has atrophied,” though “we have begun to revive it.”

She also cited the need for more progress on sensors, interceptors, and other components of the project.

Trump on Tuesday announced an initial $25 billion in funding for Golden Dome, saying its eventual cost would be about $175 billion. That figure is likely far lower than the actual price of such a system.

Thomas Roberts, assistant professor of international affairs and aerospace engineering at the Georgia Institute of Technology, said the price estimate was “not realistic.”

“The challenge with the statements from yesterday is that they lack the details needed to develop a model of what this constellation would really look like,” he said.

Not Holding My Breath

Earlier this month, the non-partisan Congressional Budget Office (CBO) estimated the cost of space-based interceptors to defeat a limited number of intercontinental ballistic missiles at between $161 billion and $542 billion over 20 years.

A system such as that envisaged by Trump “could require a more expansive SBI (space-based interceptor) capability than the systems examined in the previous studies. Quantifying those recent changes will require further analysis,” the CBO said.

The Golden Dome concept — and name — stem from Israel’s Iron Dome air defense system. But the United States’ missile threats differ significantly from the short-range weapons that Iron Dome is designed to counter.

According to the Pentagon’s 2022 Missile Defense Review, Beijing is closing the gap with Washington in ballistic and hypersonic missile technology, while Moscow is modernizing its intercontinental-range missile systems and developing advanced precision strike missiles.

The document also said the threat of drones — which have played a key role in the Ukraine war — is likely to grow, and warned of the danger of ballistic missiles from North Korea and Iran, as well as rocket and missile threats from non-state actors.

Chad Ohlandt, a senior engineer at the RAND Corporation, said “the threat is clearly getting worse,” but the “key question is how to most cost-effectively counter” it.

“Any questions of realism or feasibility for the Golden Dome depend on where we set the bar. Defend against how many threats? Threats of what capability? What is to be defended? As you raise the bar, it becomes more expensive,” Ohlandt said.

Thomas Withington, associate fellow at the Royal United Services Institute, said “there are a number of bureaucratic, political, science and technological milestones that will need to be achieved if Golden Dome is ever going to enter service in any meaningful capacity.”

“It is an incredibly expensive undertaking, even for the US defense budget. This is serious, serious money,” Withington said.

“I’m not holding my breath as to whether we will actually ever see this capability.”