Amongst contemporary systems, the Russian S-400 has been perceived as one of the most advanced air defence system. With a layered defence of 4km, 120 km, 250km and 400km respectively, the system is claimed to cover a wide range of aerial threats ranging from aircraft, Unmanned Aerial Systems (UAS), ballistic and cruise missiles. In South Asia, the S-400 was perceived as a one-stop solution for protecting India’s airspace against aerial threats. In fact, the system was tagged as Sudarshan Chakra in India, signalling divine power. However, the recent India-Pakistan conflict has helped debunk such heightened claims.
Till now, three batteries have been deployed by India near the border region, with the remaining two expected to be delivered in late-2025 and 2026. The technology is aimed at augmenting India’s layered defence system comprising Prithvi Air Defence System (PAD), Advanced Air Defence System (AAD), Barak-8 Medium-Range Surface-to-Air Missile System, Aakash Area Defence Missile System, and National Advanced Surface-to-Air Missile System II (NASAMS-II)
India’s S-400 system made its debut in South Asia in the recent Indo-Pak standoff, where the robustness of aerial assets was extensively tested via the use of aircraft, missiles, loitering munitions and advanced drones. One key takeaway from the brief conflict appears to be the vulnerability of the system. This is despite official claims from the Indian Air Force of its robustness.. While such high-profile systems may serve symbolic or deterrent functions, their limited coverage often creates exploitable gaps, enabling the intrusion of aerial assets
It has been claimed that a Chinese-made CM-400AKG air-to-surface missile, launched by Pakistan Air Force JF-17s was used successfully against the S-400 batteries in Adampur and Poonch, inflicting damage to the radar components. In order to refute the claim, Prime Minister Modi’s media team used an image of an S-400 launcher in the background of his address at Adampur base. However, the image of the intact launchers does not negate Pakistan’s stance. Merely attacking the launchers is not the only way to render an ADS ineffective given that the same can be achieved via attacking its radars, sensors and network nodes. The fact remains that during combat, the S-400 failed to intercept or protect against the downing of six Indian aircraft by the Pakistan Air Force (PAF). Notably, Pakistani JF-17s, operating well within the S-400’s stated engagement envelope, evaded detection and successfully penetrated the defensive shield to strike at the system’s radar. This reflects PAF’s effective use of deception, strong electronic jamming, and BVR strike capabilities.
The fog of war further complicates air defence operations. On May 7th, India deployed nearly 70 aircraft against 42 advanced Pakistani jets creating overlapping tracks that strained its air defence system (ADS). Low- and high-altitude threats can also challenge the system’s readiness, with success rates varying across different target types, including ballistic and cruise missiles. Integration is further hampered by India’s multi-origin arsenal from the United States, Israel, Russia, and France, which limits interoperability and network cohesion. Pakistan’s use of largely Chinese-sourced air defence systems removes this level of complexity. Compounding this is the lack of seamless coordination between the Indian Army, Navy, and Air Force, undermining unified ADS performance. Hypersonic technology adds a new layer of complexity for any ADS.
While the S-400 is technically mobile, its relocation is logistically complex and resource-intensive. Each battery comprises heavy transporter-erector-launchers (TELs), multiple radar units, command and control vehicles, and trained personnel making rapid redeployment during conflict both time-consuming and operationally demanding. Relocation also creates a vulnerability window that can be exploited through preemptive strikes.In future aerial engagements, such gaps are likely to be targeted further exposing system weaknesses and shaping the evolving dynamics of air warfare.
This recent Indo-Pak conflict demonstrated the notable role of aerial assets in future conflicts. In the past, saturation attacks in the Russia-Ukraine conflict, Iran-Israel and Israel-Hamas conflicts have also highlighted the limitations of ADS where even robust systems failed to intercept incoming aerial projectiles. In the South Asian context, where adversaries are in close proximity, such vulnerabilities become even more pronounced. Although large-scale saturation attacks have yet to occur, they remain a critical factor that could redefine regional air defence dynamics in the future. It is also important to assess whether India has acquired the 40N6 missile from Russia, as this component is critical to achieving the S-400 system’s extended 400 km engagement radar. If the 40N6 missile has been withheld, it could substantially limit the system’s operational effectiveness.
Too much reliance on Anti Area Access Denial?
Technologies such as the S-400 can provide nations with an overriding peception of security and invulnerabilty. This can lead states to cross certain military thresholds, bringing them to a level of hubris and brinkmanship that they might otherwise avoid. These perceived advantages often mask critical vulnerabilities, which become evident in operational contexts, prompting a reassessment of and role of such systems in potential conflict scenarios. While having advanced technologies is important, optimal performance is always realised through effective training, innovative integration, improved concepts and leadership. In combat, it is a fully integrated kill chain influences the overall outcome of an engagement rather than merely a platform versus platform contest.
The recent Indo-Pak crisis has punctured the hype surrounding India’s S-400 acquisition, revealing the limits of even the most advanced air defence systems. It serves as a stark reminder that technological superiority alone may not offer perfect security. Strategic overreliance on such platforms inevitably carries with it a margin of vulnerability and in high-stakes conflict, that margin can prove decisive. The ADS vulnerabilities that have now come to light are likely may impact future procurement patterns of the S-400.
Shaza Arif
Shaza Arif is a Senior Research Associate at the Centre for Aerospace & Security Studies (CASS), Islamabad. She can be reached atcass.thinkers@casstt.com.