On Tuesday, the White House released Donald Trump’s executive order to build an “Iron Dome for America” missile defence shield.
If the highly ambitious project stays true to the wording in Mr Trump’s directive, US allies in the Middle East could benefit from the “dome” because the order says associated systems will protect “allied territories, troops, and populations”, including those countries where US forces are stationed.
Mr Trump’s “next-generation missile defence shield” will involve a mix of technology that sounds like science fiction, equipment already in orbit and on the ground, as well as some technology that is decades old.
What is Trump's Iron Dome?
But what exactly has Mr Trump called for? Firstly, the term Iron Dome is misleading. The Israeli system is used for short-range air defence, to intercept rockets and drones at altitudes and distances up to 70 kilometres, but more often at close range.
Mr Trump's reference to reviving the Ronald Reagan-era Star Wars programme, technically the Strategic Defence Initiative, is more accurate, referring to defending America from the “catastrophic” threat of “ballistic missiles,” which, fired from many thousands of kilometres away, descend from space at thousands of kilometres an hour.
The US Minuteman III Intercontinental Ballistic Missile (ICBM) for example, reaches speeds of 24,000 kilometres an hour on its descent, although this slows considerably once back in the Earth’s atmosphere.
Star Wars was, Mr Reagan promised, “a vision of the future,” that would give Americans “hope” that the Soviet Union’s arsenal of tens of thousands of nuclear missiles could be blunted with space-based lasers or missiles.
“Current technology has attained a level of sophistication where it’s reasonable for us to begin this effort. It will take years, probably decades of effort,” Mr Reagan said, announcing the plan in 1983.
But the budget, initially put as high as $1 trillion or more, eventually withered by the 1990s, after a growing chorus of scientists said much of the technology was far off, while the US's main nuclear adversary, the Soviet Union, collapsed.
Mr Trump’s order says the Reagan effort “was cancelled before it could be realised,” warning that “the threat of attack by ballistic, hypersonic, and cruise missiles, and other advanced aerial attacks, remains the most catastrophic threat facing the United States.”
A clear danger for US planners would be China, with a rapidly growing arsenal of several hundred nuclear weapons. The US and Russia both have roughly 1,700 deployed nuclear weapons, similar numbers because of nuclear disarmament treaties which are now fraying. Both have several thousand such weapons in reserve.
There were thought to be about 70,000 nuclear weapons in the mid-80s, enough to destroy the world several times over. But experts warn even a war where several hundred were used could cause global environmental damage and kill millions.
Mr Trump mentions “rogue adversaries,” almost certainly North Korea, which has nuclear-capable missiles thought to be able to hit the US mainland, and Iran, which the UN says could be capable of developing a nuclear bomb.
Space Force boosted
Much of the technology mentioned in Mr Trump’s executive order already exists, albeit in an early stage. It calls for the “development and deployment of a custody layer of the Proliferated Warfighter Space Architecture.”
PWSA is, according to the US Department of Defence, a “network of hundreds of optically connected satellites,” that will be able to track hypersonic missiles and aircraft, as well as support forces on the ground spotting enemies in far-flung locations and guiding attacks against them. About 27 of a projected 500 are already in space, although testing of their laser communications systems is ongoing.
This might cover Mr Trump’s call to defend against “advanced cruise missiles.” The latter could be Russia’s in-development Burevestnik, a nuclear-powered cruise missile said to have unlimited range. The advantage of such a weapon is that, unlike ballistic missiles that can be spotted far from the mainland by radar beams pointing high above Earth, cruise missiles can fly under the radar horizon, close to the ground, making detection difficult until the last minute.
But 54 satellites in a “tracking layer,” could – according to the Space Development Agency, a part of Space Force – track these low flying weapons almost anywhere.
That would include the Middle East because, the order says, “the Secretary of Defence shall direct a review of theatre missile defence posture and initiatives to identify ways in which the United States and its allies can … Improve theatre missile defences of forward-deployed United States troops and allied territories, troops, and populations.”
To an extent, this is already the case. A constellation of satellites high above Earth, the Space Based Infrared System (SBIRS) detected Iranian missile launches in 2020, giving early warning to US forces under attack, and last year, helped defend Israel during two Iranian ballistic missile attacks.
SBIRS, which is undergoing an upgrade, can track and identify missile types, as well as giving an estimated impact point, within seconds.
Stopping the smaller “theatre ballistic missiles,” used against Israel is the job of the US Aegis system, THAAD and Israel’s Arrow, but stopping the much faster ICBMs is a tougher task.
Warheads on ICBMs – sometimes several are carried for each weapon – are extremely hard to shoot down with other missiles, although in 2020 the US Aegis Ballistic Missile Defence system intercepted a target representing an ICBM.
The US already has the Ground-based Midcourse Defence system, which is claimed to be able to offer “limited” protection for the US and Canada against ICBMs, coordinating with early warning satellites.
Mr Trump’s vision would boost this capability with “proliferated space-based interceptors.” It’s not clear what this means, but could refer to reviving a project like Brilliant Pebbles, a 1980s plan to send over 1,500 satellites into space which could then launch interceptors to crash into Soviet nuclear missiles not long after their launch.
Mr Trump’s plan also references “non-kinetic” capabilities, which could be a reference to cyber attacks to disrupt missile launches, or even sabotage operations within enemy states like North Korea.
