Droning On - How Does the UK Defend Against Air Attack?

In his keynote speech at DSEI, the UK Chief of Defence Staff, Admiral Sir Tony Radakin, noted the rise in Kamikaze drones and the risk to UK infrastructure from missile attack. There is currently no real ability to defend against surprise attack in the UK homeland, with no missiles deployed to shoot down incoming threats, and no batteries of anti-aircraft guns ready to fight off drone swarms. If a hostile power like Russia chose to launch such an attack today, could the UK really respond? The answer is probably no.

On a wooded hill in south London, there is a small neglected concrete plinth that looks like a bandstand, looking out across the City of London. Today it lies all but forgotten, but over 100 years ago it was an anti-aircraft battery designed to shoot down Zeppelins and bombers attacking London. The need to defend the capital against aerial attack is far older than people suspect and a role that has continued until the present day. The history of anti-aircraft defences in the UK is all but forgotten, but represents a fascinating insight into British defence planning. Most popularly associated with WW2 when hundreds of sites around the UK, but particularly focused on the East coast and around major cities and anchorages deployed a range of heavy guns, searchlights and barrage balloons to defend against air attack. Tens of thousands of women and men were deployed as part of ‘Anti Aircraft Command’ to provide an integrated defence system working between all three services to reduce the risk of air attack. 

In popular memory these sites ceased to play a role after 1945, but in fact the UK reinvigorated AA defences in the early 1950s to guard against Soviet attack. The threat this time was assumed to be long range Soviet bombers (ironically including stolen copies of the B29 bomber) carrying conventional and potentially atomic weapons. Defence planning of the period assumed a slow build up to war and a sustained period of conventional warfare, so it was though that major cities would be attacked as they had been in WW2. Around the UK several hundred sites were prepared to defend major cities, using a mixture of 3.7” and 5.25” guns to protect key locations. Dozens of sites had these guns permanently fixed in place, while others were held ready for reinforcement in wartime drawing on guns held in depots. In 1951 nearly 700 sites were identified for use to provide AA defence from Soviet attack Dozens of heavily reinforced Anti Aircraft Operation Rooms (AAORs) were built to coordinate the defence of key locations, squat windowless buildings that could withstand significant punishment.  It was only in the mid 1950s when the nature of warfare changed with the emergence of the hydrogen bomb that these plans changed.

By 1956 AA Command was a memory with the sites shut down and closed – the AAORs becoming nuclear bunkers (some of which survive to this day as museums), with a combination of the reduced air threat, growing risk from ballistic missiles with nuclear warheads being used in much shorter timescales than previously assessed and the end of National Service meaning a loss of manpower and wartime reserves to staff these sites. Instead resources were diverted into missiles, seeing the emergence of the Thunderbird and Bloodhound missiles that would provide layered air defence both for the Army and RAF sites. For the remainder of the Cold War the majority of UK ground-based air defence was built around SAM sites to protect key V Force air fields (and later tactical nuclear units), relying on Bloodhound firing at medium range, and Rapier at close range. Gun batteries almost completely vanished from service, although some Oerlikon were captured in the Falklands and issued to the RAuxAF.

The end of the Cold War and consequent Defence Reviews saw the assessment that the threat to the UK homebase was significantly diminished – there would be no hordes of long range Soviet bombers flying to attack UK cities and airfields. The Bloodhounds were quickly disposed of without replacement, plans to acquire Patriot being scrapped. Rapier soldiered on and was upgraded, although heavily reduced in number, and with the RAF Regiment losing its Air Defence role, relying on the Royal Artillery as the sole user of Rapier. The result was by the early 2010s, with the assumption that UK forces would operate in locations of air superiority and minimal air threat, ground based air defence was essentially on life support with minimal investment or capability. Why spend money on something that you didn’t need to use? Despite this Rapier and Type 45 played a joint role in monitoring London’s airspace in the 2012 Olympics, with Rapier batteries deployed to Blackheath common, using an old TA Barracks site on the heath (a good reminder of the value of the Volunteer Estate for this sort of operation). The resurgent Russian threat in recent years has seen more investment in air defence, with Rapier being replaced by the Sky Sabre system, providing a significantly enhanced range and capability. It is now being introduced to service and is operated by the Royal Artillery, alongside a variety of shorter range SAMS. But the days of fixed anti-aircraft batteries and artillery have gone forever – or have they? 

This CDS speech raises the fascinating question of how the UK shifts its defence planning to cope with the new threat to the homeland posed by aerial attack. As the Ukrainians have shown, widespread use of disposable drones is very much the future of warfare – cheap and effective, sending dozens, if not hundreds of drones into an attack where they can inflict damage as they hit the ground is how many opponents will fight in future. We need to be ready to operate in a world where the air threat is real – not from highly advanced £100m 5^th Generation fighters, but from £10,000 drones that are designed to be flown into the ground and destroyed. Most nations will run out of ammunition long before the attacker runs out of the ability to 3D print or make cardboard drones. This forces us to ask how would we defend against a credible swarm attack? While the chances of Russia being stupid enough to fire missiles intentionally at UK infrastructure without warning is exceptionally unlikely, it is still sensible to ask how the UK could protect its CNI from attack.

The problems raised here are significant – how do you shoot down a drone effectively – there are emerging CUAS systems entering use, but these require investment of people, training and resources to use. The warning time of a drone attack may be minimal – we have to assume it would be carried out from people operating inside the UK, potentially using drones legally imported and then converted illicitly before being sent on their way. This requires a significant mentality shift to be able to spot and defend a drone attack, and also have the means to do so. At its most basic, what Rules of Engagement do you use – if you want to shoot down a drone, this means potentially firing live ammunition over UK land where there may be civilians around, putting them at risk – given that the Home Office isn’t allowed to shoot down drones illegally delivering drugs to prisons for fear of harming prisoners (!), what hope is there of getting these risks signed off in peacetime?  How do you enable military units to shoot down a drone threat in peacetime without causing an unnecessary risk to life to others, and what happens when the rounds fired miss?

What we’re seeing then is a blurring of the problem of defending military and security sites from larger scale attack in a peacetime environment where there is very low risk appetite and a deep mistrust of using drones. Look at how, for all the talk of drone use, it is still incredibly difficult to do more than very basic activity outside of carefully segregated and controlled airspace in the UK. There are too many authorities and regulatory bodies and too little desire to take ownership of solving these risks. It is hard to see the UK being able to deploy a credible counter drone threat because of the difficulty in training and exercising to defend against it.  The challenge isn’t so much technical but legal and policy bound. There are doubtless ways that the UK could put a ring of steel (so to speak) around core sites and anchorages if it wanted to, but getting the ROE permissions to do something in peacetime is likely to be impossible.

This problem becomes even more magnified if we think about how to defend against surprise missile attack. Unlike during the Cold War there are no active SAM sites in the UK, and no missiles are deployed to protect key sites on a routine basis. To move to this would require significant investment in new capabilities and people to put in place a role that would be stupefyingly dull 99.99% of the time –working in a SAM site protecting a location that hasn’t been attacked in over 80 years is unlikely to be a retention positive opportunity for most service personnel. The messaging too is unlikely to be easy – look at the way local media reacts to changes, such as the rumours that RAF Lakenheath will be hosting US nuclear capable F35s – people panic and assume they’ll become a target (spoiler alert, if RAF Lakenheath isn’t already a target then Russian targeteers have really failed). One can only imagine the NIMBY like behaviour as people find out their local village or town will play host to an active SAM site to defend somewhere else …

From a Royal Navy perspective, the Type 45 is well placed to carry out ballistic missile defence (BMD), but there are only 6 of them. If the decision is taken that protection of the homebase is a key priority, then this forces difficult decisions on the planners to work out how to balance off protection of fleet assets like the carriers and LPDs with protecting London from possible threat. This means making strategic decisions on what matters more and how the UK can balance off commitments with only 2-3 available hulls. There simply aren’t enough air defence assets to do everything at the moment.

Looking ahead, the UK is not alone in facing these threats – every NATO nation will need to consider its resilience in the face of low technology drone attacks and how it can counter them. There will need to be serious analysis on how to put in place effective and affordable air defences that can counter drone swarm attacks which can be launched by both state and non state actors in a way that is proportionate and doesn’t cause more harm than good. The dilemma is that shooting down a drone with a missile may be effective, but reduces stockpiles at a time when its far quicker to build a replacement drone than missile. Add to this the huge minefield of complexity that is ROE and the legal risk of engagement and its easy to realise that defending against a swarm attack is likely to be a difficult and complex problem.