Clive Williams | One year on in Ukraine: can Western tanks turn the war?

The only one of those hopes that's likely to be fulfilled is the phased arrival of 157 Western third generation tanks. (Third generation tanks have thermal imagers, digital fire control systems, and composite armour.)

Russia is losing a lot of military equipment and men but can afford to lose a lot more before the conflict becomes unsustainable. On the plus side, it's ridding itself of a lot of its jail population (40,000 so far), who are being sent to the front lines to fight and become cannon fodder. Russia could probably continue to fight at the current rate of conflict for several years, but probably without making significant territorial gains beyond the 15 per cent of eastern Ukraine (not including Crimea) that it currently occupies.

At the same time, Ukraine probably lacks the military capability to expel Russian forces from the occupied areas of the Donbas region or Crimea.

Ukraine is using substantial American resources to fight the Russians, including the use of more than 5000 155mm artillery shells a day - a faster rate than the US and NATO can manufacture them. The same situation apparently applies to smart weapons. It's not clear whether this is due to Ukraine's wasteful use of munitions or the intensity of the Russian offensives.

The 157 promised tanks are 14 British Challenger 2s, 112 German Leopard 2s (only 14 to be provided in the short term) and 31 American M1A2 Abrams tanks - delivery date unspecified but will depend on availability of the less capable export version of the M1A2 Abrams. In addition, Ukraine could end up with some Leopard 2s from other countries that use them, as well as 100 older refurbished Leopard 1s.

Ukraine is accustomed to operating the second-generation Soviet T-72 tank, which weighs 46-48 tonnes and entered production in 1973. (A second generation tank is equipped with night vision devices, a stabilised main gun, a mechanical fire control system, and sometimes NBC protection.)

The strengths of the T-72 are its low weight (for a tank), basic operating system, low cost, simple and rugged design (making it highly reliable and easy to maintain in field conditions), and functionality in a variety of roles, including main battle tank, infantry support tank, and tank destroyer. It has a powerful125mm main gun making it highly capable in combat - if the tank is well concealed.

The T-72's weaknesses are its limited armour protection against modern anti-tank weapons, relatively low top speed (making it less effective in fast-moving operations), outdated fire control system, and interior space that's cramped and uncomfortable (which can affect the crew's performance).

The cost of the T-72 tank is estimated to be between US$1-2 million. By contrast, the Challenger 2 is estimated to cost around US$7 million, the Leopard 2 around US$10 million, and the M1A2 Abrams tank around US$8.5 million.

How do the promised Western third generation tanks compare with each other?

All three have very good 120mm guns. If armour protection is the priority, the Challenger 2 may be the best tank. If mobility is the top priority, the Leopard 2 is the best tank. If a well-rounded tank is what is needed, the M1A2 Abrams may be the best tank (depending on what is included in the export version).

All three also have limitations.

The British Challenger 2 is heavy (62 tonnes), which makes it difficult to transport and manoeuvre. Its fire control system, while advanced, is complex and difficult to use, requiring additional crew training.

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The German Leopard 2 is vulnerable to mines and IEDs, which can cause significant damage and disable the tank. Some critics say this is due to its lighter weight of 55-60 tonnes. Its advanced electronics and systems make it vulnerable to electronic jamming and cyberattack.

The American M1A2 Abrams is even heavier (at 68-70 tonnes), which limits its transportability and mobility. Its fuel consumption is high, reducing its operational range and making it vulnerable to fuel supply disruptions.

Without any Western tanks, Ukraine could probably field around 600 tanks, mostly T-72s. (Compared to Russia's 2600 tanks.) Western tanks will arrive slowly and in comparatively small numbers and are unlikely to make a significant difference on the battlefield in 2023, particularly as Ukrainian crews will have been fast-tracked through Western training programs and lack experience. A further problem for Ukraine is that damaged Western tanks will have to be backloaded to NATO workshops for repair.

One year on, there seems to be greater acceptance by the US that Ukraine will need to engage in negotiation to resolve the conflict, with both President Joe Biden and the Chairman of the Joint Chiefs of Staff General Mark Milley saying the conflict will probably end up at the negotiating table.

A protracted conflict would be less in Ukraine's interest than Russia's, although both will be debilitated if the conflict drags on for several years. It will also result in more destruction of Ukraine's civilian infrastructure and the loss of many more Ukrainian lives. Russia seems less concerned about the cost in Russian lives.

It had been said that the US was prepared to fight to the last Ukrainian - but noting the US leaders' comments about negotiation, that may no longer be the case. At the same time, some European NATO members seem increasingly nervous about Ukraine widening the conflict to draw in NATO members. If Ukraine can achieve a battlefield victory in 2023, that might be the time for Ukraine to head to the negotiating table.