Trump’s new missile shield for the US – challenges and dangers

A week into office, United States President Donald Trump surprised the world and many of his policymakers by announcing his plans to create a missile defence shield, calling it the “Iron Dome for America”.

At first, the name evoked Israel’s Iron Dome air defence system, which is designed to intercept and destroy low-level targets, rockets, mortar shells and cruise missiles over a short range. It is tailored to Israel’s defence needs and size.

However, the continental United States is vast, spanning four time zones, and has an extensive coastline.

It soon became apparent that what Trump was advocating on January 27 was the creation of a “new-generation missile defence shield for the United States, against ballistic, hypersonic, advanced cruise missiles, and other next-generation aerial attacks”. Essentially, it is an updated version of former US President Ronald Reagan’s Strategic Defence Initiative, or “Star Wars” programme.

The phrase “Iron Dome” is now a synonym for “missile defence shield”.

This new multilayered defence system is envisaged as not just protecting the US but also forward-deployed troops in combat.

Reagan’s dream of a missile defence shield remained mostly that, a dream, although billions of dollars were poured into the programme.

The problems, both then and now, were that a comprehensive missile shield would be exorbitant in price, barely technically possible and impractical in reality as easily available technologies would be able to spoof or overwhelm the most up-to-date missile defence system.

However, the science behind missile defence has advanced greatly in 40 years, and missile defences have now been tested in combat in Ukraine and Israel, and they are increasingly effective.

Missile defence – the art of the possible

The US already has an early warning and interceptor system in place, but this has limited ability and would be able to stop only the kind of attacks launched by minor nuclear powers like North Korea.

It would not be able to stop a large-scale attack by a determined and capable foe like Russia or China. Missile defence has matured rapidly as advancements in missile guidance and detection have increased dramatically over the past decade.

The analogy of “hitting a bullet with another bullet” hints at the scale of the challenges for developing a missile defence system, except missiles move at upwards of 20 times those speeds. For a missile defence shield to be viable, incoming missiles need to be swiftly detected and tracked, and all that information must be relayed to interceptor batteries. The interceptor must then be guided to the target, destroying the incoming enemy missile.

This, preferably, should be as far away from one’s territory as possible, especially when considering these missiles could very well be nuclear armed.

The US and Israel have poured billions of dollars into research, often cooperating, and the results are evident.

In the conflicts over the skies of Ukraine and Israel, incoming missiles have been detected and destroyed with increasing frequency.

The information gained in actual combat has been invaluable to developers. A next-generation missile shield, according to the White House, would have to defend itself against “ballistic, hypersonic, advanced cruise missiles, and other next-generation aerial attacks from peer, near-peer, and rogue adversaries”.

This is a colossal task. Modern long-range missiles come with decoys and other penetration aids. Their speed is tremendous at 25,000 kilometres per hour (15,500 miles per hour) or faster.

Missiles are launched from US HIMARS systems in northern Australia as part of joint military drills called Exercise Talisman Sabre in Shoalwater Bay on July 22, 2023 [Andrew Leeson/AFP]

Missile defences work, in part, by predictability. A person can catch a thrown ball because they know how balls move through the air in a predictable arc.

Hypersonic missiles are designed to circumvent this and take a randomised path to their targets, making their interception that much harder. Cruise missiles, first developed as offensive first-strike weapons, fly below radar cover and arrive at their targets with little to no warning.

The challenges these types of missiles create are enormous, and stopping them would require new networks, capabilities and weapons to be effective.

Enter the US Space Force

Initially derided, the US Space Force, created by Trump during his first term in office and established in 2019, would be an integral part of this new missile shield along with the US Strategic and Northern commands.

Emphasis has been placed on intercepting any missile attack as early as possible, ideally in the first phase, or “boost phase”, of a missile’s flight.

Such interceptions would require a network of space-based radar systems to detect the heat plumes of missiles that have just launched.

The plan also calls for a series of space-based interceptors that could destroy missiles at this early stage.

Whether this means interceptor missiles or introducing space-based laser batteries in orbit remains to be seen.

Space-based laser technology has significantly advanced since the 1980s when such weapons were first proposed. However, it still needs more investment and miniaturisation before it becomes a viable weapons system.

What would power a laser with sufficient strength to destroy a missile from hundreds of kilometres away as its target moves at increasing speed?

Tactical, short-range laser technology has been used to intercept targets in Ukraine, but the power needed to destroy incoming missiles would be a magnitude greater. Space-based “kinetic kill” missiles could also be used to hit and essentially smash incoming missiles to bits.

All these weapons would be in orbit, covering a huge area, as they watch for missile launches and attacks.

The placement, coordination and control of this vast network of interceptors and detectors would be controlled by the Space Force, now given an increasing “warfighter” role, using active weapons systems against an adversary.

Move and countermove

How would adversaries react? Likely by boosting weapons programmes of their own and dramatically accelerating the arms race that already exists between the nuclear-capable powers.  The technology is already out there to easily overwhelm a missile defence shield’s ability to detect and intercept every launch.

No system can be 100 percent effective – so success, or failure, would be a matter of degree. How big a degree depends on the measures used by US adversaries.

Apart from decoys, basic countermeasures already exist. Mirrored surfaces would weaken the power of any laser beam aimed at them. Warhead shrouds, fitted with liquid nitrogen coolant, can mask the temperature of incoming warheads, so early warning infrared detectors would not be able to see them.

The technologies to trick a system, still in the embryonic stages of development, are much cheaper than the missile defence shield itself.

It is increasingly likely that the tens of billions of dollars allocated for research will mushroom into hundreds of billions with every development by the US foiled for a fraction of the cost.

Increased danger

The colossal cost and technical challenges aside, there is another major issue. Embedded in Trump’s executive order is a request to pursue capabilities to “defeat missile attacks prior to launch” – in other words, attack first. This puts a very different spin on what has always been billed as a defensive weapons system but will now have an offensive component.

The order also calls for the technology to “guarantee its secure second-strike capability”. The US already has a very robust second, or retaliatory, strike capability: Its fleet of nuclear missile submarines would be able to destroy the planet several times over with the firepower they have.

The capability to strike back at an enemy who has attacked the US would be supplemented by surviving land-based missiles, air-launched missiles from airborne bombers and a variety of other delivery systems.

The US’s second-strike capability is guaranteed, so why is there a need for a shield?

An effective shield breaks down the decades-old balance of terror on which mutually assured destruction, or MAD, is based: We all can destroy each other, even if attacked first, so let’s not start a nuclear war that would result in everyone’s destruction.

This balance is significantly weakened if one party can hide behind an effective missile defence system, safe in the knowledge that if it attacks first, the new and much-improved missile shield could stop the weakened retaliatory response.

This shift in balance is particularly dangerous because it sends a signal to near-peer competitor countries, prompting them to take countermeasures of their own.

The world has become much more dangerous, and space is about to become much more crowded.