As the Indian Air Force (IAF) prepares to celebrate Air Force Day on October 8, Air Chief Marshal Amar Preet Singh’s recent announcement has drawn attention to a critical aspect of India’s defense modernization—the delivery of the Russian-made S-400 air defense systems. India has already received three of the five regiments it ordered, with the final two expected to arrive by the end of 2025. This timeline, while reassuring, raises broader questions about India’s long-term air defense strategy in the face of evolving geopolitical realities and technological advancements.
The S-400 “Triumf” is one of the most sophisticated surface-to-air missile systems available, capable of engaging a range of airborne threats, including aircraft, cruise missiles, and ballistic missiles, at distances up to 400 kilometers. For India, acquiring these systems is a cornerstone of national defense, particularly given the twin strategic challenges posed by China and Pakistan. However, the circumstances under which India is acquiring these systems—amidst US sanctions against Russia and the threat of sanctions under the Countering America’s Adversaries Through Sanctions Act (CAATSA)—are far from straightforward.
India first signed the $5.43 billion contract for five S-400 regiments in October 2018, but the delivery timeline has been extended due to a variety of factors. The last S-400 system will be delivered in 2025, nearly seven years after the original agreement. During this period, the S-400 system itself has seen rapid evolution. Russia’s strategic imperatives—particularly in response to Western sanctions following the 2014 annexation of Crimea and the ongoing war in Ukraine—have driven substantial upgrades to the system’s capabilities.
Since the start of Russia’s Special Military Operation (SMO) in Ukraine in February 2022, the S-400 has been extensively deployed and battle-tested. This high-intensity operational environment has spurred enhancements to its radars, interceptors, and command systems. However, these developments may not fully benefit the Indian Air Force due to the geopolitical complexities surrounding India’s defense relationship with Russia. While India has thus far managed to avoid CAATSA sanctions thanks to the contract’s pre-sanction timeline, the broader issue of US pressure on nations dealing with Russia remains unresolved.
When the S-400 deal was first signed, the IAF had ambitions to acquire additional regiments and even manufacture some of the system’s subsystems domestically under a technology transfer (ToT) arrangement. However, the political climate has since changed dramatically. As the US and its allies impose more sweeping sanctions on Russia, the potential for India to face penalties for further purchases of Russian defense equipment looms large.
The question, then, is whether the Indian government is in a position to sign follow-up contracts for more S-400 systems. While India has demonstrated strategic autonomy in its foreign policy, balancing ties with both Russia and the US, there is no denying that US influence could complicate further acquisitions. This is especially critical at a time when India is seeking closer defense cooperation with the US, as demonstrated by joint exercises, defense agreements, and procurement of advanced American defense technology, such as the AH-64 Apache helicopters and C-17 Globemaster aircraft.
A plausible scenario is that the Indian government, to avoid the appearance of succumbing to US pressure, might emphasize its “Atmanirbharta” (self-reliance) policy even more forcefully. India has, in recent years, promoted indigenous defense manufacturing as part of its broader goal of reducing dependency on foreign suppliers. This brings into focus India’s own efforts to develop a homegrown equivalent to the S-400 under “Project Kusha.”
India’s indigenous air defense initiative, Project Kusha, is intended to produce a system comparable to the S-400. The Long-Range Surface-to-Air Missile (LR-SAM) system under development is envisioned to have a strike range of 400 kilometers, which would enhance India’s air defense capabilities along its borders with China and Pakistan. However, Project Kusha is still in its early stages, and estimates suggest it could take two decades before the system reaches operational maturity.
In contrast, Russia’s S-400 is the result of over 50 years of continuous investment in integrated air defense technology. Even with a concerted effort, India is unlikely to bridge the gap in the near term. This raises a crucial point: while Project Kusha is a valuable initiative, it should be seen as a long-term complement to, rather than a replacement for, the S-400 system.
Given the rapid advancements in air defense technology and the growing missile threats from both China and Pakistan, the acquisition of additional S-400 systems remains a logical choice for India in the short to medium term. The IAF’s operational capabilities have been compromised by a 30% reduction in fighter fleet strength over the years, and the S-400 fills a critical gap in India’s defensive architecture. Manufacturing the system in India under a technology transfer agreement could place India on a more competitive footing within a decade.
However, there are potential downsides to a limited acquisition of the S-400 without a commitment to follow-up upgrades. India’s current contract, signed in 2018, may not include the delivery of the cutting-edge 40N6 interceptor missiles, which have only recently become available for export. The 40N6 missile, which has an effective range of 380 kilometers, is designed to engage high-value airborne assets such as AWACS, bombers, and ballistic missiles. In contrast, the 48N6 interceptors that India is expected to receive have a shorter range of 250 kilometers and are less capable in certain scenarios, particularly against targets beyond radar visibility.
It’s worth noting that China, which also operates the S-400 system, has already received the 40N6 interceptors. This could leave India at a relative disadvantage, particularly in a future conflict where air superiority and missile defense would be decisive factors.
India’s historical reluctance to upgrade its Russian-supplied weapons systems in a timely manner has already resulted in operational setbacks. One glaring example is the Balakot airstrike in 2019, during which the IAF was outgunned by Pakistan’s longer-range air-to-air missiles. The Su-30MKI fighters used in the operation lacked the longer-range RVV-SD missiles, which were available but had not been integrated into the IAF’s arsenal. Similarly, there is no evidence that India has acquired the RVV-BD missiles, which have proven highly effective during Russia’s SMO in Ukraine.
The IAF cannot afford to repeat these mistakes with the S-400. Failing to acquire the most advanced versions of the system, including the 40N6 interceptors, could severely limit India’s ability to defend against the growing missile threat from its adversaries. Missile warfare, as demonstrated in Ukraine, is likely to play a decisive role in any future peer-to-peer conflict. Conventional airpower has been largely confined to the front lines in Ukraine, with deeper strikes being carried out by ballistic and hypersonic missiles. The S-400 system, with its ability to intercept such threats, will be critical to India’s defense posture in the coming decades.
One of the primary reasons for India’s acquisition of the S-400 is the growing military threat posed by China. The People’s Liberation Army (PLA) has invested heavily in both fifth-generation stealth fighters and advanced missile systems, including hypersonic weapons. China’s two regiments of S-400 systems, coupled with its indigenous missile and air defense capabilities, provide it with a formidable defensive and offensive capability.
India’s acquisition of just five S-400 regiments seems inadequate in the face of this growing threat. To ensure that it can effectively counter both Chinese stealth fighters and long-range missiles, India will need to acquire S-400 systems in greater numbers. However, with geopolitical tensions mounting and CAATSA sanctions a constant threat, India’s window to act may be closing.
The S-400 air defense system is a crucial component of India’s broader military modernization strategy, but its acquisition is fraught with both geopolitical and technological challenges. While India has successfully secured a waiver from CAATSA sanctions for its current contract, future acquisitions may not be so fortunate. Moreover, India’s indigenous efforts to develop an S-400 equivalent, while laudable, are unlikely to bear fruit for at least two decades.
The IAF’s operational capabilities could be severely compromised if it fails to acquire additional S-400 systems or upgrade its existing systems with the latest interceptor missiles. Given the growing missile threat from both China and Pakistan, the number of S-400 systems India has ordered is simply too small. Without decisive action, India risks falling behind in a critical area of defense, potentially undermining its ability to protect its airspace in the years to come.
