A “major gap” in British defence leaves the country and its overseas territories vulnerable to ballistic missile attacks, military experts told GB News.
The lack of anti-ballistic missile (ABM) systems represents a critical blind spot, particularly highlighted after the Islamic Republic launched two ballistic missiles on 20 March towards the airbase on Diego Garcia in the Indian Ocean, jointly operated by the UK and the US.
“There is no ballistic missile defence… we’ve got nothing,” retired Lieutenant Colonel Stuart Crawford concurred, warning that whilst a ballistic missile strike on Britain was highly unlikely, things could change very quickly.
The US military managed to shoot down one missile at the time, with the other failing to function. Nevertheless, the attack was an alarming signal in defence circles. The incident showcased the Iranian missiles’ advanced capabilities, revealing they can travel a distance of 2,485 miles, placing Britain within range of direct strikes, as the UK is 2,400 miles from the Islamic Republic.
“Our lack of anything like a proper, integrated, layered ABM defence is a major lacuna,” said former British Army officer and defence analyst Simon Diggins.
In spite of ministerial assurances that Iran had no intention of targeting British lands, the Iranian ambassador to London, Seyed Ali Mousavi, coldly threatened that every option will be considered, including further strikes against the UK. In such a scenario, Britain would be virtually defenceless against a ballistic missile attack from Iran or any other hostile power.
On top of that, a particular threat lies in the fact that ballistic missiles fly in an arc high into the upper atmosphere, sometimes into space, before diving back towards their target at extreme speeds. In their final moments, they descend steeply at speeds exceeding Mach 10, leaving defenders with just a few seconds to react. Ballistic missiles can carry a range of payloads, from conventional explosive warheads for precision strikes to multiple nuclear warheads designed to split and strike several targets simultaneously.
“Were I still in a position to influence these matters, there is no doubt that missile defence for the mainland of the United Kingdom would be the very first item on my defence equipment shopping list,” said former Labour Defence Secretary Geoff Hoon. “It seems surprising that smaller Middle Eastern countries appear to have this capability, whereas the UK depends on a patchwork of equipment that might not be sufficient to deal with a sustained attack.”
The British defence forces have no independent equivalents to US systems such as Patriot, THAAD and Aegis, or the Franco-Italian SAMP/T, which are all capable of stopping an attack from such weapons. The UK employs the Sky Sabre system, which uses the modular Common Anti-Air missile as a highly effective defence against aircraft, drones and cruise missiles, but it cannot counter high-altitude hypersonic trajectories of ballistic weapons.
In November 2025, members of the Defence Committee found that Britain was “nowhere near” the required level of deterrence and had “almost nothing” in terms of complex missile defence. The report also warns that the UK may fail to meet its obligations under NATO’s Article 3.
Throughout the war in Iran, Royal Air Force pilots and ground crews also defended regional allies and British assets by neutralising air threats. Nevertheless, these efforts would again be largely ineffective against ballistic missiles. Six Royal Navy Type-45 destroyers employ the advanced Sea Viper system, capable of intercepting ballistic missiles. However, these defences are “entirely dependent” on the destroyers being combat-ready, a fact that was recently called into question following the prolonged deployment of HMS Dragon in Cyprus.
“Of the six ships in that class, four are currently in “kit form” in Portsmouth Harbour, HMS Duncan is also alongside in Portsmouth undergoing “routine maintenance,” whilst the sixth, HMS Dragon, is now undergoing “maintenance” in the Mediterranean, following its recent deployment of just three weeks,” Diggins explained. “In short, we do not have a reliable ship-based system,” he warned.
In addition, some have expressed concerns that in the event of an attack on the UK, it is unlikely that help could be expected from allies, particularly in matters not related to NATO, such as Diego Garcia and Cyprus. The war in Iran and its aftermath have also highlighted the potential fragility of military alliances, particularly NATO, following criticism from US President Donald Trump.
Despite these concerns, a spokesperson for the Ministry of Defence issued a statement saying that the UK has “the resources we need to keep the United Kingdom safe from attacks, whether it’s on our soil or from abroad. The UK stands ready 24/7 to defend itself, and as a founding member of NATO, we benefit from the Alliance’s collective defence capabilities, including its integrated air and missile defence systems.”
“The UK operates a layered approach to air and missile defence, provided by Royal Navy, British Army and Royal Air Force assets equipped with a range of advanced capabilities, working in tandem with our NATO allies. This Government has made air and missile defence a priority after years of underfunding. That is why last June, following the Strategic Defence Review, we announced up to £1 billion in new funding to strengthen our defences and keep the UK secure. This investment also boosts the UK’s contribution to NATO, ensuring we play our part in protecting our allies and ourselves,” added the spokesperson.
