In January of 1946, Yugoslavia accepted a communistic government aligned with the Soviet Union. This allowed for political and military relationships with the Soviet Empire and, thusly, Yugoslavia obtained a local-production license to manufacture the new T-72 Main Battle Tank of 1971 as the M-84 (slightly modified to suite Yugoslavian Army requirements). The original T-72 was developed as an economically-minded end-product to complement the more expensive T-64 for the Red Army as only premiere frontline Red Army units would be issued the limited-number T-64. The T-72 was subsequently offered for export and it was through this endeavor that the T-72 proved exceedingly popular with production numbers exceeding 25,000 worldwide (compared with the modest 13,000 presented by the T-64 which was never sold overseas). Locale production of the T-72 was also handled in Poland and Czechoslovakia.
Utilizing the T-72 as a starting point, design work on the localized Yugoslav M-84 spanned from 1979 to 1983. Initial prototypes were produced in 1982 and 1983. The tank made use of a locally-developed fire control system (FCS) and was given an uprated 1,000 horsepower diesel-fueled engine over that of the T-72's original 780 horsepower fitting. Armor protection was improved and incorporated broader use of composite alloys. The tank retained the capable 125mm smoothbore main gun as well as its autoloader, the latter reducing the operating crew from four (common to Western tanks) to three (commander, gunner and driver). Externally, the M-84 presented the same general overall appearance of the T-72 including its shallow profile (thanks in large part to the two-man turret and autoloading facility). Likewise, the running gear consisted of six double-tired, rubber-coated road wheels to a track side with the drive sprocket at rear and the track idler at front. Side skirt armor was fitted over the upper portions of the tank treads for basic protection. The M-84 hull sat atop a torsion bar suspension which allowed for excellent cross-country mobility. Range was out to 700 kilometers with a top road speed of 68 km/h.
The 125mm 2A46 smoothbore main gun was the same tank gun as fitted to the T-72 and the upcoming T-80 for the Russian Army. Onboard stowage allowed for 42 x 125mm projectiles to be carried, usually as a mix of various armor-defeating warhead types (HE-FRAG, HEAT-FS and APFSDS-T). Additionally, the gun could fire guided anti-tank missiles from the barrel, a Soviet/Russian tank design staple never wholly adopted in the West. Utilizing the automatic loading carousel, the projectiles and charges were loaded individually from two rungs, the ammunition type selected electronically by the gunner per the commander's order. Low-flying aerial threats were countered by a 12.7mm heavy machine gun at the commander's cupola (right side of turret roof). As standard, a 7.62mm machine gun was fitted in a coaxial position next to the main gun. 300 rounds of 12.7mm ammunition was carried as was 2,000 rounds of 7.62mm ammunition. Smoke grenade dischargers were retained along the front sides of the turret, five in a bank on the right and seven in a bank on the left.
After the requisite trials, the M-84 was officially adopted by the Yugoslavian Army and introduced in 1984 (hence its designation). Production would span from 1984 to 1991 to which some 652 examples were produced. Exportation of the M-84 occurred only to the Kuwaiti Army and fewer than 200 examples were delivered in all. By this time, the local political climate in Yugoslavia had changed considerably following the fall of the Soviet Union in 1991. As such, Yugoslavia entered a period of consistent upheaval which resulted in the various "Yugoslav Wars" of the 1990s. Born from the ashes of fighting were the nations of Croatia, Macedonia, Bosnia and Herzegovina, Serbia and Montenegro and Slovenia. The various wars also curtailed much of the intended production concerning M-84 tanks.
The original Yugoslavian M-84 production mark proved to be the "M-84A". An Armored Recovery Vehicle (ARV) version became the "M-84AI". The first major upgrade in the M-84 line was the "M-84AB" which introduced an upgraded fire control system, integrated laser rangefinder and various modernized optics. A related version, the M-84ABN, was unveiled with new navigational equipment. The command tank version of the M-84AB - outfitted with additional communications equipment - became the "M-84ABK".
With the break-up of Yugoslavia, the now-independent states inherited existing stocks of existing M-84 tanks and eventually worked in modifying them to local army requirements. Serbia evolved their stock to produce the "M-84AS" designation which included a new fire control system, new armor scheme, Agava-2 thermal imaging device, 1,200 horsepower diesel-fueled engine, support for Russian "Kontakt-5" series Explosive Reactive Armor (ERA) blocks. Additionally, the main gun now supported the newer Russian AT-11 "Sniper" anti-tank guided missile. As in modern Russian Army tanks, the Serbian M-84 adopted the "Shtora" anti-missile countermeasures system. The M-84AS was first debuted in 2004 and shares similarities in equipment and capabilities with the Russian Army's T-90S variant.
Croatia went in its own direction to produce the accurized M-84A4 "Sniper" mark. This version was given an improved fire control system, all-new optics and a new engine of 1,100 horsepower output. The M-84A4 mark was subsequently was adopted as the new Croatian Army standard MBT. More recently, the Croatian Army has been developing the "M-84D" as a new standard. ERA block armor is supported and a remote weapons station (RWS) has been added to the commander's cupola, allowing for the machine gun to be fired from within the safety of the vehicle. A new 1,200 horsepower diesel engine has been selected and the communications suite upgraded. The autoloader is further streamlined for and an increased rate-of-fire. Formal adoption of the M-84D mark is thought to have occurred sometime in 2011.
Croatia has been developing the M-95 "Degman" as the chosen successor to the M-84 with the project ongoing since the mid 1990s. The M-95 is a direct modernization of the M-84 system (therefore a descendant of the T-72) with an all-new composite/reactive armor protection scheme. However, the project has been limited to just two completed prototypes as of 2012 with the long-running intent being procurement of around 40 M-95 tanks for the Croatian Army.
The M-84 was readily available during the Yugoslav Wars of the 1990s and managed a modest combat history in the conflict. Guerilla tactics proved popular against enemy tanks and this decimated M-84 stocks especially when armor lacked the supporting infantry to defend it. This also proved the case with the Soviet Army and its new T-80 MBTs in the First Chechen War, hundreds lost to rocket-propelled grenade attacks from all angles in the urban fighting environment.
The Kuwaiti Army had obtained the M-84 (M-84AB) prior to the Persian Gulf War of 1991. However, these stocks were largely restricted from frontline combat due to their T-72 resemblance. Kuwait eventually procured 149 M-84 tanks and several command tank (ABK) versions.
The Yugoslav Army operated approximately 450 M-84 tanks prior to the breakup of the country. From this, Bosnia and Herzegovina obtained sixteen M-84 tanks while the Croatians claimed some eighty-four units. Serbia manages a healthy stable of 212 M-84 tanks across four active battalions. Slovenia received 54 M-84 tanks after the breakup.