Chandigarh: Amid endless plans and discussions to modernise India’s military, one issue that receives far less attention than it deserves is the extraordinary diversity of equipment and systems operated by all three services. This not only imposes a hugely expensive logistical burden, but also complicates maintenance, training, interoperability and sustainment on a scale few major militaries would willingly tolerate.Over decades, India has sourced assorted materiel from more than 20 countries, like Russia/Soviet Union, France, the US, Israel, Britain, Germany, Sweden, Italy, Switzerland, Ukraine, Poland, Brazil, the Czech Republic, South Korea and Spain and several other countries, creating an inventory of exceptional breadth and complexity.The resulting mix of combat aircraft, helicopters, tanks, artillery, missiles, air defence systems, unmanned aerial vehicles (UAVs), warships, submarines, radars, electronic warfare equipment, communications networks and countless other systems has produced an inventory of staggering complexity that is costly, labour-intensive and increasingly difficult to sustain.Every additional military platform and piece of equipment brings its own supporting ecosystem – distinct supply chains; inventories; spare parts; maintenance, repair and overhaul infrastructure; training pipelines; technical documentation and broader upkeep architecture.Beyond the financial implications, such diversity also imposes significant strain on supply-chain management and operational efficiency. Over time, the proliferation of disparate equipment and systems generates an administrative overhead far higher than that of a more standardised force built around common equipment and interoperable systems.Moreover, a significant proportion of equipment across all three services also incorporates imported sub-systems and components, many of which are no longer in production. In many instances, this has compelled the development of expensive, often indigenised substitutes produced in limited quantities, or the continued operation of ageing components through jugaad or localised innovation. The outcome is a fragmented maintenance system in which outdated equipment, reliance on multiple suppliers, and small-scale production all add to maintenance difficulties and increase overall lifecycle costs.The financial impact of supporting this extraordinary diversity of equipment and systems across the armed forces is reflected in India’s steadily rising revenue expenditure on their operation, maintenance, including repairs, spares, training, logistics and related support functions.According to the Ministry of Defence (MoD) budget estimates, spending on stores, equipment repair and refits increased by almost 20% between financial year (FY) 2024-25 and FY 2026-27, rising from Rs 57,726.37 crore to Rs 68,784.05 crore.Yet, these amounts almost certainly understate the true cost. Official sources indicated that once revised estimates and actual expenditure on maintaining the extensive inventory of platforms and equipment across the three services are incorporated, the final outlay is likely to be much higher.Air ForceThe Indian Air Force (IAF) perhaps best illustrates this complex inventory.Its combat fleet alone comprises six different fighter aircraft types from different generations.These include the Soviet/Russian MiG-29s and Su-30MKIs, French Mirage-2000Hs and Rafales, Anglo-French Jaguars and variants of the indigenous Tejas Mk1/1A Light Combat Aircraft. Until its retirement in September last year, after 63 years of service, the Soviet-era MiG-21 ‘Bis’ too was among the IAF’s frontline fighters, having remained in service through successive – and expensive – life-extension programmes, well beyond its originally envisaged total technical life.A MIG-29k takes off from INS Vikrant. Photo: Government of India, GODL-IndiaThe IAF’s transport and helicopter fleets, too, are similarly diverse.The former include US-origin C-17 Globemaster IIIs and C-130J Super Hercules, Soviet-era IL-76s/IL-78s (refuellers), AN-32s, licence-built German Dornier Do-228s and Airbus C295s. The IAF’s helicopter inventory comprises Russian Mi-17V5s, Mi-17 variants, Mi-26 heavy lifters and Boeing AH-64E ‘Apache’ attack and CH-47F ‘Chinook’ heavy-lift platforms.Additionally, it also operates Hindustan Aeronautics Limited (HAL)-series built Dhruv Advanced Light Helicopter (ALH) in multiple variants (Mk I-IV), with the Rudra as its weaponised derivative. The HAL-manufactured Prachand light combat helicopter (LCH) and light utility helicopter represent separate, but developmentally linked rotorcraft that evolved out of the broader Dhruv design and engineering ecosystem.An IAF Il-78 refuels a Su-30 MKI mid-air. Photo: X/@IAF_MCC via Wikimedia Commons.ArmyThe Indian Army too faces a similar challenge because of the extraordinary variety of its weapon systems, vehicles, aerial assets and support equipment in its inventory.Its armoured vehicle fleet, for instance, includes three main battle tanks: the Soviet/Russian-origin upgraded T-72M1 ‘Ajeya’ and T-90S ‘Bhishma’, and the indigenously designed Arjun; by 2028-29, these will be supplemented by the under-development ‘Zorawar’ light tank.Each of these platforms employs different engines, transmissions, fire-control systems, ammunition support arrangements and maintenance procedures. Consequently, upholding separate supply chains for three current and, in due course, four tank types significantly increases inventory costs and complicates operational planning.The T-90 ‘Bhishma’. Photo: PIB via Wikimedia Commons.The Army’s artillery inventory is equally heterogeneous.It includes imported FH-77B Bofors 155mm/39 calibre howitzers, Dhanush guns – an indigenous upgrade derived from the same Bofors lineage – the K9 Vajra-T self-propelled 155mm/52 calibre howitzers based on a South Korean design, and imported ultra-light BAE Systems M777 155mm/39 calibre guns, supported through limited in-country integration and assembly arrangements.These are further augmented by Sharang guns – Soviet-era 130mm M-46 field guns upgraded and re-barrelled to 155mm/45 cal standards and named after the divine bow in Hindu mythology – as well as Pinaka multi-barrel rocket launcher systems, Smerch long-range rocket systems and Soviet-era BM-21 Grad multiple rocket launchers.File image of an M777 system alongside its ammunition. Photo: Jonathan Mallard/Wikimedia Commons/CC BY 2.0.The Army’s air defence inventory is arguably among the most diverse in the world, encompassing indigenous, Soviet, Russian, Israeli and Western-origin systems, spanning multiple generations of technology.It includes the indigenously developed Akash medium-range surface-to-air missile (SAM) system alongside an assortment of Soviet and Russian-origin equipment, including the S-400 Triumf long-range air defence system, Pechora (S-125) low-to-medium altitude SAM system, the OSA-AK short-range mobile air defence system, the Igla human-portable air defence system and the ZSU-23-4 Shilka self-propelled anti-aircraft gun.Also in service is the upgraded legacy 40mm L-70 Bofors anti-aircraft gun from the 1940s, many examples of which have been fitted with indigenous fire-control and targeting systems. These are further supplemented by Israeli-origin systems, most notably the SPYDER quick-reaction SAM system for low-to-medium altitude air defence, together with associated radar and sensor suites, including the EL/M-series developed by ELTA Systems.The Army’s Akash air defence system. Photo: PIB via Wikimedia Commons.Together, many of these systems are integrated with multiple imported and locally developed radars, creating a multi-layered, but highly diverse air defence architecture. Each system, however, brings its own command interfaces, maintenance protocols, ammunition standards, training pipelines and logistical requirements, resulting in a fragmented sustainment ecosystem. The operational outcome is therefore a patchwork Integrated Air Defence System in which standardisation, interoperability and logistical efficiency remain structurally constrained by the very diversity that underpins its utility.The Army Aviation Corps (AAC) adds another layer of complexity to the forces’ overall inventory.It operates licence-built Chetak (French-origin Aerospatiale Alouette III) and Cheetah (French Aerospatiale SA 315B Lama) utility helicopters, indigenous Dhruv ALH and its Rudra armed derivative, and is progressively inducting the indigenous Prachand LCH. Adding to its rotary assets, the AAC is currently in the process of inducting six Boeing Apaches acquired under a $930 million contract signed in 2020, which will be based at Jodhpur.Furthermore, the Army’s small arms inventory reflects a layered mix of legacy and modern systems sourced, once more, from sundry origins. It includes Russian Kalashnikov series rifles like AK-47s and AK-103s, the phased-down Indigenous Indian Small Arms System or INSAS assault rifles as well as the US-made SIG Sauer SIG716 G2 rifles. These are further complemented by Israeli-origin Tavor TAR-21 and IWI X95 assault rifles, along with Soviet Dragunov SVD, Israeli Galil and Finnish Sako TRG-42 sniper rifles.A Galil sniper rifle. File image via US Marines/Wikimedia Commons.NavyLikewise, the IN also operates a remarkably diverse inventory of warships, submarines, naval aircraft, weapons, sensors and support equipment drawn from a range of foreign and indigenous sources.Its underwater fleet alone comprises four distinct platform classes: the licence-built French Kalvari (Scorpene) class, the Russian ‘Kilo-class and the German-origin Shishumar (HDW Type 1500)-class, conventionally powered attack submarines (SSKs), in addition to the locally developed and built Arihant-class nuclear-powered ballistic missile submarines (SSBNs).Presently, the Navy is on the verge of signing a Rs 70,000 crore contract with Mazagon Dock Shipbuilders Limited for the construction of six next-generation SSKs under Project 75(I), in collaboration with Germany’s ThyssenKrupp Marine Systems (TKMS). Based on TKMS’s Type 214 design lineage and equipped with air-independent propulsion and land-attack capability, these boats will add a fourth class of SSKs to the Navy’s inventory, bringing the total number of submarine types and classes in service to five.Maintaining separate dockyard expertise, crew training establishments, spare-parts inventories and industrial support arrangements for each conventional submarine class, while also sustaining SSBNs and preparing for future nuclear-powered attack submarines or SSNs, imposes significant demands on resources and a specialised labour force.The Indian Navy’s INS Aridhaman, its third indigenously built nuclear-powered ballistic missile submarine, Photo: @JM_Scindia/X via PTI.The IN’s surface fleet is equally diverse.It operates two aircraft carriers – the retrofitted INS Vikramaditya (formerly the Soviet Admiral Gorshkov) and the indigenous INS Vikrant – alongside Kolkata-, Visakhapatnam- and Delhi-class destroyers; Shivalik-, Nilgiri- and Talwar-class frigates; Kamorta- and Kora-class corvettes; missile boats, amphibious vessels, survey ships and numerous auxiliary craft.Even vessels performing broadly similar missions frequently employ different propulsion systems, sensors, weapons and combat management suites, adding further complexity and expense to overall maintenance and support.Naval aviation presents an additional sustainment challenge.The Navy currently operates Russian-origin MiG-29K carrier-borne fighters and, in April 2025, signed a Rs 63,000 crore inter-governmental agreement with France for 26 Dassault Rafale M aircraft. The acquisition, which includes weapons, simulators, training, logistics support, maintenance packages and upgrades, will create a second carrier-based fighter ecosystem with its own distinct features.And, looking further ahead, the indigenous Twin Engine Deck-Based Fighter, currently under development and tentatively slated for induction in the mid-2030s or thereabouts, will add a third carrier fighter type, further complicating sustainment and fleet management.The INS Vikramaditya and INS Vikrant aircraft carries with other vessels. Photo: X/@IndianNavy via Wikimedia Commons.Beyond its combat aircraft, the IN also operates US-origin Boeing P-8I and HAL-built Dornier Do-228 maritime patrol aircraft, Sikorsky/Lockheed Martin MH-60R Seahawk helicopters, Russian-origin Kamov Ka-28 anti-submarine warfare and Ka-31 airborne early warning helicopters, indigenous ALH Dhruv naval variants, Chetak utility helicopters and a small number of Sikorsky Sea King helicopters.Collectively, these aircraft add yet another layer of complexity to an already diverse inventory of equipment and systems.But this bewildering assortment of conventional military equipment and systems is far from complete.BrahMos and UAVs perform service-specific roles across IAF, Army and NavyIndia’s deep-strike capability, anchored by BrahMos cruise missile variants, developed in conjunction with Russian assistance, is fielded across all three services, though in distinct operational roles and deployment architectures. For now, these conventionally armed systems constitute a service-specific precision-strike capability, forming a distinct gradation between traditional artillery and rocket forces and strategic deterrent assets within India’s conventional warfighting structure and force posture.Consequently, the Army employs land-based mobile regiments for conventional deep-strike and interdiction missions, the Navy integrates ship-launched variants for maritime strike and sea denial roles and is developing a submarine-launched BrahMos version, while the IAF operates air-launched configurations from Su-30MKIs for long-range precision engagement.BrahMos. Photo: PIB via Wikimedia Commons.Furthermore, in keeping with the changing character of warfare, the three services are also fielding a rapidly expanding inventory of unmanned aerial systems (UASs), further adding to the diversity of equipment that needs to be maintained, supported and integrated with existing operational assets.These include Israeli-origin Heron and Searcher surveillance UAVs and Harop loitering munitions, and indigenous systems like Nishant, Netra, Rustom-II/TAPAS-BH and Archer, along with a growing range of weaponised tactical UAVs and drones developed by India’s defence industry. Additionally, all three services operate an expanding array of smaller reconnaissance and strike drones procured from multiple domestic manufacturers.Such platforms are often service-specific, tailored to differing operational requirements, and come with distinct sensors, data links, ground control stations, maintenance arrangements and training pipelines. Collectively, these platforms also impose a significant maintenance overhead, requiring continuous technical attention and specialised support ecosystems across services.What’s more, such UAS diversity is set to increase further with the planned induction of 31 US-origin MQ-9B Predator-series drones with 16 SeaGuardian variants for the Navy and eight SkyGuardians each for the Army and the IAF, under an estimated $3-4 billion deal cleared in late 2024, with inductions expected 2029 onwards.File image of a Heron UAV. Photo: IDF via Wikimedia Commons.While these systems will considerably enhance the military’s overarching intelligence, surveillance and reconnaissance and strike capabilities, they will also add yet another dimension of logistical, technical and operational complexity to an already diverse materiel inventory.Military planners, meanwhile, attribute this vast equipment diversity to decades of strategic necessity, shifting geopolitical alignments, technology transfers, evolving operational requirements and the gradual maturation of India’s indigenous defence industry.Industry officials, on the other hand, attribute this vast equipment diversity to lack of foresight, pragmatism and planning on the part of services and the MoD. Over time, however, new acquisitions were added in an ad hoc manner to existing inventories rather than replacing older systems, leaving a force structure shaped largely by past decisions.But as India’s armed forces ready themselves for an era of precision warfare, joint operations and multi-domain combat, the rationalisation of its sprawling materiel inventory is fast becoming a strategic necessity. Logistics, after all, win wars as surely as firepower, and force modernisation cannot simply be about acquiring new capabilities; it must also involve reducing complexity, improving commonality, and building a military that is easier to sustain, deploy and fight.