The post–Cold War era is the period in world history from the collapse of the Soviet Union on December 27, 1991 to the present. During the Cold War (12 March 1947 – 26 December 1991), the Soviet domination of the Warsaw Pact led to effective standardization on a few tank designs. In comparison, France, Germany, the United States, and the United Kingdom had previously developed their own tank designs, but now tried to standardize their designs, while the smaller nations of NATO purchased or adapted these designs.

The fall of the eastern bloc brought changes as the United States Military cut much of its expenditure, though the level rose again to comparable heights after the war on terror started in 2001.

After the Cold War, tank development continued into a third generation of main battle tanks and because of the effectiveness of antitank weapons, the technology advanced dramatically as well. Tanks became more survivable and their armour became thicker and much more effective. Fourth generation tanks are in development, with two (Japan's Type 10 and South Korea's K2) claimed as operational fourth generation tanks.

Overview

The main battle tank became the standard as a necessity, as it was realized that smaller medium tanks could carry guns (such as the US 90 mm, Soviet 100 mm, and especially the British L7 105 mm) that could penetrate any practical level of armor at long range. An increasing variety of anti-tank weapons and the perceived threat of a nuclear war prioritized the need for additional armor. The additional armor prompted the design of even more powerful cannons. Typical main battle tanks were as well armed as any other vehicle on the battlefield, highly mobile, and well armored.

Developments

In 1974, the United States initiated an impressive programme to modernise its existing tank fleet and start real mass production of the M60A1, and later the M60A3; at the same time the M1 was developed. Budgets for tank design and production picked up during the administration of president Ronald Reagan, following tensions between the United States and the Soviet Union.

In response to infantry-portable and vehicle-mounted ATGMS, ever more capable defences were developed. Spaced armour, composite, explosive reactive armour, and active protection systems—like the Russian Shtora, Drozd, and Arena—were added to old and new tanks. Despite these improvements, the larger missiles remained highly effective against tanks. This was demonstrated in 1991 during the Gulf War when during a friendly fire incident, Hellfire anti-tank missiles disabled several M1 Abrams tanks.

Some of the most successful second-generation Cold War tanks are still in service, indeed, some are still being built. However, they have been extensively upgraded and in some cases overhauled repeatedly and even completely rebuilt during the ensuing decades with layers of enhanced modern armor, newer guns, electronics and brand new and very different engines. Notable examples would be the T-72, Merkava and M1 Abrams. Sometimes these complete overhauls are given a new name, like the Polish Army's PT-91 Twardy based on the T-72M1 (upgrade) which derives from the T-72.

Gulf War/Iraq war

Operation Desert Storm in 1991 saw the US Marines still charging in with their M60 tanks while the rest of the tank forces had the Abrams. The Iraqi forces were initially regular army units, equipped with tanks such as T-54/T-55 tanks and T-62s. The Coalition main battle tanks, such as the U.S. M1 Abrams, British Challenger 1, and Kuwaiti M-84AB were vastly superior to the Chinese Type 69 and domestically built T-72 tanks used by the Iraqis, with crews better trained and armoured doctrine better developed.

The majority of Iraq armored forces still used old Chinese Type 59s and Type 69s, Soviet-made T-55s from the 1950s and 1960s, and some poor quality Asad Babil tanks (domestically assembled tank based on Polish T-72 hulls with other parts of mixed origin). These machines were not equipped with up-to-date equipment, such as thermal sights or laser rangefinders, and their effectiveness in modern combat was very limited.

The Iraqis failed to find an effective countermeasure to the thermal sights and sabot rounds used by the Coalition tanks. This equipment enabled them to engage and destroy Iraqi tanks from more than three times the range that Iraqi tanks could engage coalition tanks. The Iraqi crews used training rounds against the U.S. and British tanks. These rounds (purchased in great number during the Iran–Iraq War due to their cheap price) had soft steel penetrators and thus no hope of penetrating the advanced Chobham Armour of the Coalition tanks.

In Operation Iraqi Freedom in 2003, an Iraqi division the 6th Armored Division of the Iraqi Army.Lee, R. J. Key Components of the Iraqi Ground Forces, 2002 which was equipped with T-55s and BMP-1s defending the control of key bridges over the Euphrates River and the Saddam Canal at Nasiriyah, were decimated by US Marines with M1 Abrams, and the division as a unit rendered incapable for combat during the Battle of Nasiriyah in March 2003, during the invasion.

In addition to the T-54/T-55 and T-62 tanks that Iraq had, the most feared to US armoured forces were the T-72 tanks in the Iraqi forces. Only Republican Guard divisions were equipped with Iraqi-modified T-72s. Many of the Iraqi T-72s were dug-in or hidden in groves, and then used to ambush the US or British tanks. In the war, the Iraqi T-72s were the preferred target for Apache helicopters and A-10s, in an attempt to diminish the combat power of Republican Guard divisions. The only chance for the Asad Babil T-72s against American tanks was to lure them to close range combat, or trying to ambush them from dug-in positions.Scales, page 269: "As TF 1-37th Armor crossed over the ridge into the heart of the Iraqi defensive zone, the Iraqi commander's carefully disposed rear-slope defense stripped Dyer's tanks of their range advantage. Within 1,000 meters, a row of dug-in T-72s and BMPs suddenly appeared below the crest. All were hull-down in prepared positions behind thick dirt walls (thus disproving the much-quoted u.s. truism that soviet tanks had difficulties in achieving 'hull down' position). Now the Americans were well within Iraqi killing range, and although the Soviet-made night sights were markedly inferior, things could still get very dicey."

But even in those conditions, the M1s usually prevailed, as proven in circumstances like the Battle of Baghdad, and the drive to the capital, where dozens of Iraqi MBTs were obliterated,Scales, page 270: "After the war they (TF 1-37th) returned to count the burned-out hulks of 76 T-72s, 84 BMPs, 3 air defense artillery pieces, 8 howitzers, 6 command vehicles, 2 engineer vehicles, and myriad of trucks." or near Mahmoudiyah, south of Baghdad, April 3, 2003, (Iraqi Freedom) when US tanks engaged their counterparts from just 50 yards, shattering seven enemy T-72s without losses.Conroy & Mars, p. 158 The Lion of Babylon T-72 was utterly outclassed by the M1 Abrams, the Challenger and by any other contemporary Western main battle tank during the 2003 invasion of Iraq.

Main battle tanks introduced during the post-Cold War era

Merkava Mark IV

The Israel Defense Forces Merkava Mark III was introduced in December 1989, and had upgrades to the drivetrain, powertrain, armament, and electronic systems. The most prominent addition was the incorporation of the locally developed IMI 120 mm gun. This gun and a larger diesel engine increased the total weight of the tank to , but the larger engine increased the maximum cruising speed to .

The turret was re-engineered for movement independent of the tank chassis, allowing it to track a target regardless of the tank's movement.

The next development was the Israel Defense Forces Merkava Mark IV tank which is the most recent upgrade of the Merkava tank and has been in development since 1999. The upgrade's development was announced in an October 1999, however, new Merkava Mark IIIs continued to be produced until 2003. The first Merkava IVs were in production in limited numbers by the end of 2004.

The model has a new fire-control system, the El-Op Knight Mark 4. Removable modular armor, from the Merkava Mark IIID, is used on all sides, including the top and a V-shaped belly armor pack for the underside. This modular system is designed to allow for damaged tanks to be rapidly repaired and returned to the field. The tank carries the Israeli Elbit Systems Battle Management System and an active protection system.

Tank rounds are stored in individual fire-proof canisters, which reduce the chance of cookoffs in a fire inside the tank. The turret is "dry"; it stores no active rounds.

Some features, such as hull shaping, exterior non-reflective paints, and shielding for engine heat plumes mixing with surrounding air to confuse enemy thermal imagers, were carried over from the IAI Lavi program of the Israeli Air Force to make the tank harder to spot by heat sensors and radar.

The Mark IV includes the larger 120 mm main gun of the prior versions but can fire a wider variety of ammunition, including high-explosive anti-tank (HEAT) and armour-piercing fin-stabilized discarding sabot (APFSDS) kinetic energy penetrator rounds, using an electrical semi-automatic revolving magazine for 10 rounds. It also includes a much larger 12.7 mm machine gun for anti-vehicle operations (most commonly used against technicals).

T-90MS

Leclerc Série XXI

The Leclerc is the French main battle tank (MBT) built by GIAT, now Nexter of France. It was named in honour of General Philippe Leclerc de Hauteclocque who led the French element of the drive towards Paris while in command of the Free French 2nd Armoured Division (2ème DB) in World War II.

The Leclerc is equipped with a GIAT (Nexter) CN120-26 120 mm smoothbore cannon. This cannon can fire the same NATO standard 120 mm rounds as the German Leopard 2 and US M1 Abrams, but in practice, only French-produced ammunition is issued. The gun is insulated with a thermal sleeve and has an automatic compressed-air fume extraction system instead of the usual bore evacuator. The Leclerc has a unique autoloading system which was specifically designed for it, and reduces the crew to three by eliminating a human loader. The turret of the Leclerc was designed around the auto-loading system to avoid the problems common to other tanks with an autoloader. The Leclerc autoloader allows a rate of fire of 12 shots per minute and holds 22 rounds of ready ammunition; it can accommodate up to six different types of ammunition at once, although like most autoloader systems it cannot change ammunition types once a round has been loaded. The most common types are the armour-piercing fin-stabilised discarding sabot (APFSDS) kinetic energy penetrator with a tungsten core and the high-explosive anti-tank (HEAT) round. There are 18 other rounds available for reload. A Leclerc tank can fire while traveling at a speed of 50 km/h on a target 4,000 metres away. The gun is 52 calibres long instead of the 44 calibres common on most tanks of the Leclerc's generation, giving the rounds a higher muzzle velocity.

The Leclerc is also equipped with a 12.7 mm coaxial machine gun and a remote-controlled 7.62mm machine gun, whereas most other NATO tanks use 7.62mm weapons for both their coaxial and top machine gun mounts; the major exception is the American M1 Abrams, which has a 7.62mm coaxial machine gun and two top-mounted machine guns, one 7.62mm and one 12.7mm.

The Leclerc has the GALIX combat vehicle protection system from GIAT, which fires a variety of smoke grenades and infra red screening rounds, as well as anti-personnel grenades.