March 31, 2015:   A Russian motorized infantry brigade in Western Siberia recently received fifteen modernized T-72B3 tanks. This is a modernized version of T-72 with an improved fire control system and next-generation communications equipment. The delivery was of the Russian effort to modernize its armed forces. Russia has over 5,000 T-72 tanks in use (2,000 in active service and 3,000 in reserve) and most of them are Cold War (pre-1991) vintage and seriously out-of-date compared to American, European and Chinese tanks.

The T-72 is a Soviet second-generation tank that entered production in 1971. About 20,000 T-72 tanks were built, making it one of the most widely produced post–World War II tanks, second only to the T-54/55 family. The T-72 was widely exported and saw service in 40 countries and in numerous conflicts. Improved variants are still being built for export customers. The T-72 was the most common tank used by the Warsaw Pact from the 1970s to the collapse of the Soviet Union. It was also exported to other countries, such as Finland, India, Iran, Iraq, Syria, and the former Yugoslavia, as well as being copied elsewhere, both with and without licenses.

Licensed versions of the T-72 were made in Poland and Czechoslovakia, for other East European countries. These tanks had better and more consistent quality of make but inferior (to Russian made models) armor, lacking the resin-embedded ceramics layer inside the turret front and glacis armor. The Polish-made T-72G tanks also had thinner armor compared to Soviet Army standard (410 mm for turret). Before 1990, Soviet-made T-72 export versions were similarly downgraded for non-Warsaw Pact customers (mostly the Arab countries). Many parts and tools are not interchangeable between the Russian, Polish and Czechoslovakian versions, which caused logistical problems.

The T-72 shares many design features with earlier Soviet tanks. Some of these are viewed as deficiencies in a straight comparison to NATO tanks, but most are a product of the way these tanks were envisioned to be employed, based on the Soviets' practical experiences in World War II. The T-72 is extremely lightweight, at forty-one tons, and very small compared to their Western counterparts. Some of the roads and bridges in former Warsaw Pact countries were designed so that T-72s can easily use them while NATO tanks could not pass at all, or only at very low speed.

The basic T-72 is relatively underpowered, with a 780 hp (580 kW) supercharged version of the basic 500 hp (370 kW) V-12 diesel engine block originally designed for the World War II-era T-34. The 0.58 m (23 inch) wide tracks run on large-diameter road wheels, which allows for easy identification of the T-72 and descendants (the T-64/80 family has relatively small road wheels).

The T-72 has a comprehensive nuclear, biological, and chemical (NBC) protection system. The inside of both hull and turret is lined with a synthetic fabric made of boron compound, meant to reduce the penetrating radiation from neutron bomb explosions. The crew is supplied clean air via an extensive air filter system. A slight over-pressure prevents entry of contamination via bearings and joints. Use of an autoloader for the main gun allows for more efficient forced smoke removal compared to traditional manually loaded ("pig-loader") tank guns, so NBC isolation of the fighting compartment can, in theory, be maintained indefinitely. Exported T-72s do not have the anti-radiation lining.

Armor protection of the T-72 was strengthened with each succeeding generation. The original T-72 turret is made from conventional cast armor. It is believed the maximum thickness is 280 mm (11 inches), the nose is about 80 mm (3.1 inches) and the glacis of the new laminated armor is 200 mm (7.9 inches) thick, which when inclined gives about 500–600 mm (20–24 inches) thickness along the line of sight. Late model T-72s feature composite armor protection.

The T-72A featured a new turret with thicker but nearly vertical frontal armor. The cast steel turret included a cavity filled with quartz or sand. The T-72M (export version of the Soviet T-72A) featured a different armor protection compared to the T-72A: it had a different composite insert in the turret cavity which granted it less protection against HEAT and armor-piercing (AP) munitions. The modernized T-72M1 featured an additional 16 mm (0.63 inch) of armor on the glacis plate, which produced an increase of 32 mm (1.3 inch) horizontally against both HEAT and AP. It also featured a newer composite armor in the turret with pelletized filler agent.

Several T-72 models featured explosive reactive armor (ERA), which increased protection primarily against HEAT type weapons. Certain late-model T-72 tanks featured heavy ERA to help defeat modern HEAT and AP against which they were insufficiently protected. Late model T-72s, such as the T-72B, featured improved turret armor, visibly bulging the turret front. The turret armor of the T-72B was the thickest and most effective of all Soviet tanks; it was even thicker than the frontal armor of the T-80B. The T-72B used a new "reflecting-plate armor" in which the frontal cavity of the cast turret was filled with a laminate of alternating steel and non-metallic (rubber) layers. The glacis was also fitted with 20 mm (0.8 in) of appliqué armor. The late production versions of the T-72B/B1 and T-72A variants also featured an anti-radiation layer on the hull roof.

Early model T-72s did not feature side skirts; instead the original base model featured gill or flipper-type armor panels on either side of the forward part of the hull. When the T-72A was introduced in 1979, it was the first model to feature the plastic side skirts covering the upper part of the suspension, with separate panels protecting the side of the fuel and stowage panniers.

After the collapse of the Soviet Union, U.S. and German analysts had a chance to examine Soviet-made T-72 tanks equipped with Kontakt-5 ERA, and they found this ERA impenetrable to most modern American and German tank projectiles. This sparked the development of more modern Western tank ammunition, such as the M829A2 and M829A3. Russian tank designers responded with newer types of reactive armor, including Relikt and Kaktus.– Ryan Schinault