Readers are more interested in the aircraft than the weapons that bring them down. Kenneth P. Werrell’s timeless saying is relevant in the contemporary milieu, where drones have become an inescapable feature of warfare. In the wake of the technological revolution unfolding overnight, drones are regarded as a tactical game-changer which will redefine the notions of geography and politics. These advancements raise pressing questions for the future of Air Defence Systems (ADS), critical to restrict the breakneck manoeuvres of unmanned agents in the skies.
Generally, drones are thought to have two key features that provide an offensive edge: detection-avoidance and saturation. Their small size, low-altitude flight, and slow speed reduce the likelihood of detection and interception by enemy air defence systems. Saturation tactics overwhelm countermeasures by exhausting finite munitions, reinforcing the conventional belief that modern air defences struggle against the precision and persistence of drones.
The perceived advantages of drones in detection-avoidance are more nuanced than they initially appear. While smaller sizes and stealth designs reduce radar visibility, these benefits can be mitigated by advancements in radar technology. Radar systems measure the radar cross-section (RCS) of an object using electromagnetic pulses, and the effectiveness of detection improves with higher-frequency radar pulses. Consequently, a larger RCS increases the likelihood of detection and engagement by ADS at significant distance.
For example, Medium-Altitude Long-Endurance (MALE) drones often have larger wingspans than fighter jets, making them more detectable. The MQ-9A Reaper, with a wingspan of 20 metres, significantly surpasses the F-16 Fighting Falcon and F-15 Eagle, which have wingspans of 9.8 and 13 metres, respectively. These dimensions can challenge their stealth against radars operating across various wavelengths. Even with a reduced RCS, MALE drones are not entirely immune to modern ADS. Integrated Air Defence Systems (IADS), equipped with both ground-based and airborne assets, have advanced capabilities to detect and engage targets with low RCS over extended ranges. For instance, the Russian S-400 system can detect and track objects with an RCS as small as 0.02m², highlighting the growing challenge drones face against sophisticated air defence networks.
Low-altitude skimming and slow speed are often considered key features that delay drone detection. However, these tactics are increasingly less effective against advanced, layered air defence networks equipped with a combination of airborne and ground-based assets. In recent years, states have made substantial investments in airborne radar systems, providing continuous surveillance capabilities and significantly reducing drones’ ability to exploit the Earth’s curvature for stealth. These airborne systems extend detection ranges and enhance tracking precision, undermining the low-altitude advantage. Simultaneously, ground-based air defences have integrated advanced filtering mechanisms and data analytics to distinguish slow-moving drones from environmental clutter. Once identified, these drones become vulnerable to a range of countermeasures, including anti-aircraft artillery and man-portable air defence systems (MANPADs), which are specifically designed to target and neutralise low-flying threats.
Saturation tactics are hailed as the cherry on top to overwhelm enemy ADS. However, this is increasingly challenged by advancements in modern air defence technologies, which combine robust kinetic and non-kinetic countermeasures. Recently, Poland put forward a proposal of developing missiles to counter the threat of swarm drones. Unlike traditional munitions, these missiles are capable of intercepting drones at altitudes of up to 1,500 metres, making them effective against drones operating at low and medium altitudes. With a range of 15 kilometres and laser-based guidance, the proposed system offers a promising and cost-efficient solution to counter swarm drone threats.
By integrating such innovations into existing air defence networks, states are closing the gap between the perceived advantages of saturation tactics and the realities of advanced, multi-dimensional air defence strategies. This shift underscores the ongoing arms race between offensive drone capabilities and defensive countermeasures. Hence, the evolving dynamics of drone warfare remain a challenge. The application of stealth technologies in drones is likely to reduce the detection range of air defence systems, especially when coupled with adversarial tactics such as the use of decoys and cyber-attacks. These strategies can deceive or degrade tracking capabilities, further complicating defence efforts. Plus, small drones present unique challenges. Their agility and maneuverability allow them to bypass traditional response mechanisms, often evading detection and interception. Yet, modern air defence systems are not easily outmatched. Advanced sensors, using rare earth materials like gallium oxide, are increasingly effective in countering stealth advantages, demonstrating the adaptability of these systems.
Besides this, price marker remains a significant hurdle in the face of low-cost drones. The standard munitions deployed to counter drones put an enormous strain on the coffers, making interception an inflated choice. Nonetheless, states have boosted their efforts to field affordable interceptors such as Iron Beam to keep down the high costs of countering drones.
However, the best path for aerial defence is incremental adaptation, not tectonic shifts. Thus, states need to enhance their electronic warfare capabilities to remain a step ahead of their adversaries. Furthermore, establishing robust air-gapped communication networks is crucial to processing large amounts of data securely ensuring seamless command and control operations even in the face of cyber threats.
The Russia-Ukraine war has underscored the resilience of modern air defence systems, which have cast a protective net to deny hostile use of airspace. While drones have introduced new complexities to aerial warfare, the notion that air defences have become obsolete is a misconception. Instead, they have evolved into formidable bastions, making both high-altitude and low-altitude operations increasingly perilous. As drones advance so do air defence systems which will continue to have a considerable place in military considerations.
Shaheer Ahmad is a Research Assistant at the Centre for Aerospace & Security Studies (CASS), Islamabad. He can be reached at cass.thinkers@casstt.com.
