Ex-Polish PT-91 tanks have arrived in Ukraine.

A long column of former Polish PT-91 Twardy tanks, rolling across a training ground somewhere in Ukraine on or before Monday, is a salutary reminder of two important facts.

Despite significant promises to Ukraine of Western-made tanks, upgraded Soviet-style tanks remain by far the most numbers in the Ukrainian arsenal. And it is those tanks that are likely to lead the Kyiv forces’ shift from defense to attack in the coming weeks or months.

The greatest Soviet-style tank Russia has been able to obtain in substantial quantities as of late is, however, inferior to the worst tanks Ukraine is collecting.

Russia still does not import tanks. He builds them new, locally, or restores them from local stocks of vintage Cold War vehicles. Industrial bottlenecks have choked Russia’s efforts to recover the nearly 2,000 tanks it has lost in the 14 months since it expanded its war against Ukraine.

Unmodified T-62s and T-55s from the 1960s and 1950s are increasingly being used as replacement tanks in the Russian Army since they do not require the high-tech components that are in short supply in Russia.

Instead, as Ukraine replaces the roughly 500 main battle tanks it has lost since February 2022, it is receiving many of them from foreign allies. The local shortage of electronic, optical or ball-bearing components does not limit the supply of new vehicles.

That’s why those eight PT-91s parading through that Ukrainian field this week are so encouraging to advocates of a free Ukraine. These are the tanks that Kyiv could send into battle against the old Russian T-62 and T-55.

It would be a very uneven match. To produce a PT-91, Polish vehicle manufacturer Bumar-Labedy started with a 45-tonne T-72M1 – an upgraded export variant of the 1983 Soviet T-72A – and replaced the engine, transmission, fire controls, optics and autoloader and added Polish-made Erawa reactive armor bricks.

The result is a tank that still looks a lot like a T-72. The same silhouette. The same 2A46 125-millimeter main gun. 

The same three-person crew. But it has an 850-horsepower diesel engine instead of the old 780-horsepower model, making it several miles per hour faster. Well-tuned reactive armor offers better protection against high-explosive rounds.

However, the most important feature of the PT-91 is its new fire control system. The T-72M1 stabilizer is clunky and requires frequent recalibration, limiting the tank’s accuracy when firing. The Twardy adds a new, more robust two-axis stabilization.

That is to say. The PT-91 is a better tank than a T-72M1 from the 1980s and much better than a much older T-62 or T-55. In terms of firepower and protection, the Polish-made tank could be just behind a German-made Leopard 2A4.

Poland acquired some 230 PT-91s in the 1990s. Warsaw has so far ceded 60 of them to Kyiv. More could come as new US-made Polish M-1s and South Korean K-2s start arriving in large numbers.

How many of the PT-91s have reached Ukraine so far is unclear. It is clear from the complete lack of photographic evidence of Twardys at the front that Kyiv is retaining the ex-Polish tanks, either saving them for the newly formed brigades or hoping to send them to the existing brigades as a replacement for the losses of combat.

In any case, these new PT-91s will soon outnumber Ukraine’s western main battle tanks, which include: 14 ex-British Challenger 2s; part of 40 Leopard 2A4s from Poland, Canada, Norway and Spain; and some of the latest 31 Leopard 2A6/Strv 122s from Germany, Portugal and Sweden.

Ukraine is also taking delivery of more than 100 Leopard 1A5s from a German-led consortium and 31 American M-1A1s. But none of these cars have been shipped.

If Ukraine goes on the counteroffensive this spring or early summer, the PT-91s could be the most numerous replacement tanks in the Ukrainian Army.

Luckily for the Ukrainians, they are pretty good tanks. Much better, at least, than the Russian replacement tanks.

David ax