Following the collapse of the USSR in 1991 Ukraine inherited the capacity to produce the most expensive and high-end Soviet tank class the T-80, which were being built alongside the lighter T-72s in the 1980s at three separate Soviet facilities of which one was located in the Ukrainian city of Kharkiv.
While Russia abandoned production of the T-80 in 1992 in favour of the T-72, which was widely seen to be much more cost-effective both to produce and to operate, Ukraine would continue to offer the T-80 for export and to conservatively modernise the design.
The result was the T-84 Oplot, which used a diesel engine rather than a gas turbine as most T-80s did which provided a higher endurance but also a worse performance in cold weather.
The tank used a new domestically sourced welded turret, replacing the T-80's Russian-sourced cast turret, the domestically developed Duplet explosive reactive armour and Zaslon active protection system, improved engines and an armoured ammunition compartment in a new turret bustle. With Ukraine's defence sector being much smaller than that of Russia or the USSR, and the country's own armed forces deploying no T-84s in a combat role and currently fielding less than half a dozen, the tank is considered far from cost-effective in part due to the tiny scale on which it has been produced.
Issues with the T-84, and the lack of funds available to acquire them, has led Ukrainian Army has deployed older T-64 tanks in their hundreds to the country’s eastern regions to combat Russian backed separatists. Concerns regarding the tank’s reliability are speculated to be a primary cause, and the tank notably failed to make a good impression at the Strong Europe Tank Challenge held in Germany, a Western Bloc equivalent to the Russian Tank Biathlon, where three of the four tanks saw their loaders malfunction in 2018.
Another notable issue was the tank’s shaky 125mm cannon, which seriously restricted their effective firing range - a result of problems with the fire control systems. T-84 tanks at the 2018 Strong Europe Tank Challenge saw their firepower suffer greatly as a result with less than 50% of the expected performance.
With the T-84 continuing to suffer such critical failures two decades after the first tanks rolled off production lines, Ukraine’s ability to remedy these problems was left in serious doubt.
A further issue with the T-84 program is the very limited remaining industrial capacity in Ukraine compared even to the 1990s, let alone the Soviet era. With the T-84 barely in use in Ukraine itself, the tank's primary operator is the Thai Army which placed an order for 49 tanks in 2011.
Ukraine proved unable to manufacture them at even a fraction of the speed that it had built T-80s in the 1990s, which had been exported to Pakistan, with the order taking seven years to complete. This led the Thai Defence Ministry to consider cancelling the deal while looking to China as a more reliable source of modern battle tanks.
With Ukraine increasingly reliant on imported armaments, the country may well eventually begin to consider importing foreign tanks rather than relying on its own in the distant future. A precedent for this was set by Poland, which was supplied a T-72 production line by the USSR but, after producing and upgrading some units following the Soviet collapse, would instead look to South Korea, Germany and the U.S. for supplies.
With the country’s several hundred T-64 tanks increasingly considered insufficient for its defence, and it's few T-80s in storage, the country may look to foreign tanks instead of the T-84 to counter the fast-improving capabilities of its neighbours. The considerable shortcomings of the T-84 could well mark the end of Ukraine’s attempt to become a major developer and exporter of modern battle tanks.
