“There is always a well-known solution to every human problem—neat, plausible, and wrong,” according to H. L. Mencken. Today we might ponder his words to diagnose the revival of another neat, plausible and boneheaded idea: ringing the planet with orbiting missiles to somehow make the U.S. safer.
In January President Donald Trump called for a “next-generation missile defense shield” for the U.S. in an executive order. Named an “Iron Dome for America” after Israel’s short-range missile defense system—which it has nothing to do with—the plan would pour hundreds of billions of additional dollars into the long-underperforming rathole of U.S. missile defense efforts while weaponizing space. In the order, Trump referenced then president Ronald Reagan’s 1983 initiative, known as “Star Wars,” to build a missile defense shield with ground- and space-based weapons, saying it was “canceled before its goal could be realized.”
A similar fate awaits Trump’s plan—for the same reasons that Reagan’s missile-defense fantasia, including a late-1980s orbital version known as “Brilliant Pebbles,” never panned out: it will cost too much, won’t work and will endanger us all.
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Right now the U.S. has 44 ground-based interceptor missiles stationed on the U.S. West Coast and aimed against ballistic missile attacks from the unstable nation of North Korea. They have worked 12 times out of 21 tests, a paltry success rate achieved only after $250 billion spent since their 1985 beginning. This illustrates the intrinsic, expensive difficulty of intercepting even dummy intercontinental ballistic missiles (ICBMs). It’s just hard to hit them.
What’s driving Trump’s Iron Dome? Fear of nuclear-tipped hypersonic missiles developed by Russia and China, which reach speeds of Mach 5, about one mile per second. Unlike ballistic missiles, which arc into space before returning to Earth, hypersonic ones maneuver and fly on a flat trajectory, which would be challenging for U.S. ground interceptors. “Most terrestrial-based radars cannot detect hypersonic weapons until late in the weapon’s flight due to line-of-sight limitations of radar detection,” the Congressional Research Service noted in a recent report.
In pursuit of “peace through strength,” the executive order argued, “the United States will guarantee its secure second-strike capability.” That means the ability to launch nuclear missiles as payback after a hypersonic nuclear attack on the U.S.—one that would mean World War III had started—supposedly to be assured via hypersonic-missile-detecting satellites, plus satellites to link these sensors to interceptors and the “deployment of proliferated space-based interceptors.”
The idea is that space-based interceptors would presumably get a jump on blocking missiles over the current ground-based ones. (Natch, there are also space lasers planned. Although, with apologies to Dr. Evil, we’ve yet to hear if equally impractical “sharks with frickin’ laser beams attached to their heads” will also make a debut.)
The fundamental problem with all this, of course, is that the U.S. already has a guaranteed second-strike capability, with some 900 nuclear missiles riding around on its submarines right now. This is more than China has in its entire stockpile. The whole rationale for Trump’s Iron Dome is a solution in search of a problem, the very definition of wasteful government spending. The leaders of China and Russia know launching any missiles, hypersonic or not, at the U.S. would lead to a catastrophic nuclear war that would kill five billion people, very likely including you, me and them—the last group courtesy of the U.S. Navy’s subs.
Even leaving aside this basic flaw, Trump’s Iron Dome has plenty of other problems. For one thing, many of the claims about the special threat from hypersonic weapons may be just Department of Defense hype, where their initial launch and detection wouldn’t be much different than current intercontinental ballistic missiles, as scientists reported four years ago in Scientific American.
Then there is the cost: an Iron Dome actually modeled on Israel’s short-range missile defense system, scaled up to cover the 3.7 million square miles of the continental U.S. (the contiguous 48 states plus Alaska), at $100 million per battery, would cost around $2.5 trillion, estimated nuclear policy analyst Joseph Cirincione in July. That system offers a defense only against dumb, ballistic missiles—not even addressing maneuverable, hypersonic ones. Another estimate published in 2024 by Defense and Peace Economics found such a system would cost from $430 billion to $5.3 trillion. That estimate noted the fundamental economic challenge facing missile defenses: they cost more, anywhere from eight to 70 times more, than the ICBMs they are meant to defend against. They are machines for bankruptcy.
Now, consider the difficulty: leaving aside the poor U.S. test record for its current interceptors, detecting hypersonic missiles from space might be easier than spotting ICBMs. Traveling at high speeds through the atmosphere, hypersonic missiles should generate tremendous heat, giving off a strong infrared signal to track from space. The trouble is that so would any cheap decoys released alongside them, “posing insurmountable problems for a reliable system of defense,” the New York Times observed in an analysis of Trump’s proposal.
Finally, even if somehow enacted, this whole idea makes us all less safe. Since the end of the cold war, the U.S. has proclaimed its missile defenses were not meant to block an incoming attack from China or Russia, just loose North Korean ones. This was to forestall a new arms race with China or Russia if they grew spooked that a protected U.S. would launch an unannounced first nuclear strike. Moscow has already threatened to blow through agreed limits to its nuclear stockpile following Trump’s proposal, and China was already building up its stockpile over such first-strike fears. Orbiting U.S. missiles and lasers a few hundred miles overhead of Moscow and Beijing would do little to calm nerves there, while false alarms have always been a feared potential start to World War III.
Even if missile defenses worked, any attacker could instead just threaten the U.S. with something as simple as a truck bomb, as the Congressional Budget Office noted in a 2021 report, or a nuclear drone. Nevertheless, the CBO projected a 40 percent increase in U.S. missile defense spending, an increase to $176 billion in this decade, even before the Iron Dome proposal. Two senators have already pitched a bill to steer $19.5 billion in taxpayer money to their states under its cover.
The most ludicrous thing is that even Trump knows this. “You could destroy the world 50 times over, 100 times over. And here we are building new nuclear weapons, and they’re building nuclear weapons,” he told reporters in February, calling for denuclearization and cutting Pentagon spending. “We’re all spending a lot of money that we could be spending on other things that are actually, hopefully, much more productive.”
That’s right. If Trump wants to save taxpayer dollars, instead of firing nuclear weapons safety experts, he should put a lid on his Iron Dome.
This is an opinion and analysis article, and the views expressed by the author or authors are not necessarily those of Scientific American.