Iran has quietly climbed into the ranks of the world’s top 20 military powers by dint of heavy investment in missiles, drones and asymmetric tactics rather than conventional platforms. International assessments, including a global military strength index and IISS’s Military Balance, place Tehran’s active forces at roughly 610,000 personnel, with a large reserve and a disproportionate emphasis on missile and unmanned capabilities that alter regional calculations.
The Islamic Revolutionary Guard Corps remains central to Tehran’s force posture: roughly 190,000 troops inside the IRGC control Iran’s strategic missiles, many of its unmanned aerial systems, and the expeditionary elements that operate beyond Iran’s borders. The regular army, navy and air force together account for the remainder of the manpower, but much of the conventional kit—especially combat aircraft—remains aged and technically constrained by sanctions.
Missiles have become Iran’s strategic currency. Western think tanks estimate Tehran once held between 2,500 and 3,000 ballistic and cruise missiles before last year’s confrontation with Israel, a stock that analysts say was depleted by roughly half during that exchange. Tehran still fields long-range systems that it says reach 2,000–2,500 km, and has publicly showcased indigenously upgraded systems such as the Khorramshahr-4 and other claimed long‑range and hypersonic-capable missiles.
Unmanned systems amplify Iran’s reach. Tehran has poured resources into so-called “Observer” and “Phantom” families of drones and supplied variants to foreign operators; US research centres and NATO partners have documented Iranian-made UAVs in other theatres, including Russian use in Ukraine. In last year’s fighting with Israel, Iranian forces claimed the launch of hundreds of missiles and roughly a thousand drones, demonstrating how attrition can be absorbed by domestic production and dispersed basing.
On the ground, Iran fields one of the Middle East’s largest standing armies with around 35,000 tanks and heavy artillery systems oriented to defence and attrition warfare rather than high-tempo mechanised offensives. Much of this equipment is older, modified or domestically produced iterations of Soviet, Chinese and pre-revolutionary US designs, which suits an operational doctrine focused on area denial and protracted conflict on or near Iranian territory.
The air force is the weakest link in Tehran’s conventional triad. IISS estimates around 250 combat-capable aircraft—many inherited from before the 1979 revolution—suffer from spare-parts shortages and limited modernization prospects under sanctions. Iran’s response has been to prioritise missile and drone investments that can project power and complicate adversaries’ calculations without relying on sustained air superiority.
At sea, Iran pursues a clear asymmetric doctrine: mines, small fast-attack craft armed with anti-ship missiles, coastal defences and a fleet of small submarines designed to threaten larger navies in the confined waters of the Persian Gulf. Global fleet tallies put Iran’s navy at roughly 109 vessels, including two dozen or so small submarines, patrol boats and a modest number of frigates and corvettes built for area denial rather than blue‑water presence.
Budgetary realities and strategic choices shape the limits of this capability. Stockholm International Peace Research Institute calculates Iranian defence spending at about $7.9 billion in 2024, down about 10% year-on-year in nominal terms but still above mid‑decade levels. Sanctions, inflation and oil‑export constraints have squeezed procurement, yet Tehran appears ready to channel resources into asymmetric systems and expanded domestic production—backed by recent announcements of major planned increases to defence and security allocations.
Taken together, these trends matter because they change the cost calculus for Iran’s neighbours, the US regional posture, and European security planners. A force built around missiles and drones can impose high costs on adversaries while being resilient to sanctions-driven shocks. It also complicates negotiations: Tehran’s ability to threaten strategic depths and maritime commerce gives it leverage in diplomacy and crisis bargaining, even as the country’s conventional weaknesses constrain how far it can escalate without risking broader retaliation.