In a previous article, the author emphasized the importance of mobility and suggested that India’s future-ready combat vehicles (FRCVs) should prioritize it in their design. However, focusing solely on mobility is necessary but not sufficient for developing a main battle tank (MBT). The Indian Army (IA) must integrate the FRCV in a manner that allows it to operate in coordination and synergy with other assets of the emerging Integrated Battle Groups (IBGs).
This point, though seemingly obvious, directly impacts three fundamental characteristics of tank design: mobility, protection/survivability, and firepower. Additionally, the aspect of maintainability is crucial. The Russia-Ukraine war has highlighted the benefits of Western armor, demonstrating a positive correlation between protection (in the form of heavy armor) and maintainability. This comparison will be instrumental in understanding India's warfare doctrine, especially its maneuver warfare and tank-mobility-centric Integrated Battle Groups (IBGs), which, capable of combined arms operations, offer mobility and protection while offsetting the inherent weaknesses of Indian tanks.A key takeaway for Indian planners from the Russia-Ukraine war is maintainability. While, as the author has previously argued, mobility should be prioritized in the FRCV (Future Ready Combat Vehicle) design, India's current medium-weight armored forces sometimes compromise on protection. This is precisely where Combined Arms Operations (CAO) become decisive, maximizing the effectiveness and survivability of tanks in achieving specific mission objectives. CAO will also guarantee the operational mobility of the FRCV.
Armor will play a critical role within Indian IBGs. Currently, two distinct types of IBGs are envisioned: one for China (PRC) and another for Pakistan. In November 2024, the Indian Army sought government approval for the formation of these IBGs, a request that remains pending. Each IBG is projected to comprise approximately 5,000–6,000 troops, primarily integrating mechanized infantry, artillery, armor, air defense, and Unmanned Aerial Vehicles (UAVs).
However, in late July 2025, the Indian Army decided to establish two Rudra Brigades. These brigades broadly foreshadow the potential IBGs and represent a transformation of some single-arm brigades (approximately 3,000 troops each) into multi-arm units, incorporating UAVs, infantry, mechanized infantry, anti-tank units, tanks, artillery, and Special Forces (SF). The Rudra Brigades will be deployed in selected border areas of India, but their importance is currently transitional. They are likely to serve as testbeds for future IBGs.
Future IBGs will undoubtedly be significantly larger, better equipped, and specifically trained for combined arms operations compared to the Rudra Brigades. The Modi government needs to expedite their formation. IBGs are a direct evolution of India's Cold Start Doctrine (CSD), which, though acknowledged, remains undeclared officially. The CSD aims for rapid mobilization and deployment of forces, something that was previously challenging due to the long mobilization times for India's three strike corps, historically used in offensive operations against Pakistan. These ground assaults, supported by the Indian Air Force, sought to pre-empt Pakistani defensive preparations or to restore the status quo ante by seizing enemy territory in response to an attack on Indian soil, similar to the 1965 India-Pakistan War.
Conversely, China-centric IBGs will feature a different structure. They will incorporate two new models of Light Battle Tanks (LBTs), alongside existing T-90s and older T-72s. These China-centric IBGs will be relatively lighter and reinforced with robust air support.
India's historical war experience, particularly with Pakistan, demonstrates the successful execution of armor-based maneuver operations. For example, during the Battle of Basantar in the 1971 war, the Centurion tanks of the 16th Armoured Brigade decisively defeated Pakistan's Patton tanks. This success was attributed to excellently trained tank crews, effective close fire support, and the successful navigation of minefields with the assistance of artillery and engineer regiments. This stands as a superb instance of combined arms operations, where the inherent vulnerabilities of tanks were offset by the synergistic cooperation of other military branches.
Rudra Brigades and future IBGs could partially mitigate the stringent requirement for combined arms operations if the Indian Army were to also develop heavy battle tanks, such as the British Army's Challenger 3 (66.5 tonnes, three tonnes heavier than its predecessor, the Challenger 2). These tanks are comparable in weight to the Indian Army's Arjun MkA1. The Challenger 3, operating in conjunction with combat vehicles like the Ajax Infantry Fighting Vehicle and Boxer, is designed to achieve superior fire support and mechanized dominance. Upon full operational capability by 2027, these systems will also incorporate advanced sensors and boast enhanced maintainability and modularity.
Britain's prioritization of heavy tanks stems from their focus on attritional warfare, where protection is paramount over mobility. Heavy tanks facilitate easier repair and recovery, crucially preserving the lives of trained crews. A damaged tank can have its surviving crew immediately redeployed into a new vehicle. However, replacing killed or severely injured trained crews is challenging due to the time required for extensive training. Hastily deploying inexperienced crews can exacerbate tactical situations, slow down the pace of operations, and potentially prolong wars or lead to defeat.
Despite these advantages of heavy armor, India's experience has been mixed, and at times, unsuccessful. For instance, heavy tanks like the Arjun have not been deployed in high-speed offensive operations against Pakistan. Even if they were, their sustainability and logistical footprint would be prohibitively heavy.
Transporting the Arjun tank via Heavy Equipment Transporters (HETs) presents significant deployment challenges. The Indian Army, to date, lacks any combat experience with the Arjun. Moreover, the Arjun's inherent mobility limitations would pose a significant impediment even in defensive operations within the desert terrain of Rajasthan, its probable deployment area.
Regarding the Arjun, logistical shortcomings and the repair of damaged parts during wartime present a serious challenge. Studies on its peacetime deployments have consistently revealed frequent issues with spare parts availability and repair difficulties. India has committed to high-speed offensive operations as part of its IBG strategy, a domain in which the Arjun has no practical role. In the event of armored operations with Pakistan, the Arjun's utility would be confined to mobile or blocking defensive actions—i.e., logistically sustainable defensive deployments. This was the role performed by British Challenger and American Abrams tanks against Iraq, first in deterring an Iraqi assault on Saudi Arabia, and subsequently facilitating the Allied offensive that liberated Kuwait. However, it is crucial to note that the logistical and supply burden in offensive operations—in terms of ammunition, fuel, and spares—is considerably higher. Furthermore, a significant factor in American and British success was the limited resistance they encountered from Iraq. India is unlikely to be afforded such an advantage against Pakistan.
Thus, the 68.5-tonne Arjun MkA1, being two tonnes heavier than the Challenger 3 currently under development, presents an excessively heavy logistical and maintenance burden. Consequently, India has no alternative but to prioritize mobility over protection, especially in projects like the FRCV. This prioritization is essential for effectively executing mobile offensive operations within its Land Warfare Doctrine (LWD) and achieving the limited military objectives of the IBGs.
The Challenger 3 example vividly underscores the criticality of maintainability in modern warfare. This challenge is further exacerbated for India's current tank fleet, including the T-90 and T-72, which are primarily designed for mobility rather than robust protection. The Russia-Ukraine war has unequivocally demonstrated that tanks like the T-90 are sustaining significant damage due to inadequate protection against both aerial and ground-based anti-tank threats, coupled with inherent maintenance vulnerabilities.
Nevertheless, a distinct advantage of medium-weight tanks is their superior logistical sustainability compared to heavy tanks. India's adversaries, be it China or Pakistan, are not projected to deploy extensive heavy armored forces. However, some analyses indicate that a side opting out of heavy tank deployment might incur greater losses if the opponent chooses to employ them. This particular risk would emerge if Pakistan, in the long run, decides to field a heavy tank force with Chinese assistance. Despite Russia's devastating losses in Ukraine, it is not feasible for India to fundamentally reorient its current and future armored forces beyond the framework of medium and light tanks (T-72, T-90, LBTs, and FRCV).
Conversely, the Indian Army and DRDO, along with their development partners, arguably missed a critical opportunity to pre-emptively acknowledge the benefits of heavy armor, especially within combined arms operations against Pakistan. With the Arjun MBT's failure to meet expectations, this strategic avenue is now largely closed. This constitutes yet another vital lesson from the Russia-Ukraine war.
This article draws its references and analytical perspectives from the research paper 'Indian Battle Tanks: Medium or Heavy Armour in Combined Arms' by Karthik Bommakanti, Senior Fellow in the Strategic Studies Programme at the Observer Research Foundation.