Western allies have the power to help extricate the country from the unfavourable conditions it is facing against Russia

One of the primary aspirations of professional militaries is to field a force capable of delivering victory while circumventing attritional warfare. Attritional warfare develops when neither side is able to achieve a decisive advantage. Unless new capabilities or terrain shift the logic of a fight, attritional warfare ends when one side exhausts its supply of people, materiel or morale. This is the grim state of the current fighting in Ukraine.

For Russia, the low morale and poor cohesion of its infantry prevents its army from undertaking large offensive manoeuvres without taking unsustainable levels of losses in both personnel and equipment. So far, it has lost about a quarter of its armoured forces in Ukraine.

Russia has therefore resorted to the saturation of Ukrainian positions with artillery, destroying defended villages and tree lines until Ukrainian troops are forced to withdraw, and then advancing to occupy what has been abandoned. This is slow and resource-intensive, but Russia has enough ammunition to keep up its current rate of fire for several years.

For Ukraine, the overwhelming Russian artillery advantage means that its armed forces struggle to concentrate in formations above the company group, and making progress with such a small force demands that they commit some of the country’s best troops.

Casualties among these highly proficient units has a disproportionate impact on Ukrainian military effectiveness because most of the time these veterans are distributed across the force to support less experienced troops. Ukraine, therefore, is intermittently conducting small raids when the opportunity arises, while seeking to inflict a high enough number of casualties to collapse Russian morale, enabling territory to be reoccupied.

If the rate of Russian casualties can be increased, collapse is possible. The Kremlin has avoided a declared mobilisation, preferring to covertly draw people with military experience back into the ranks. This is because many Russians are actively discussing how they can avoid the draft.

The very need for such measures is discussed in Russia as a sign of government incompetence, and the perception of incompetence undermines enthusiasm for the war, even among ardent Russian nationalists. If its troops become demoralised in Ukraine because of prolonged massed casualties, the Kremlin may struggle to find replacements.

For the Ukrainians, the existential stakes in the fighting have meant that morale is high, despite their taking up to 100 casualties a day over the last couple of weeks. Ukraine has no shortage of military volunteers but it does have a shortage of equipment for them. Ukraine’s greatest immediate vulnerability is its ammunition stocks.

It has almost expended its Soviet-era ammunition for key systems and is now dependent on a limited number of Nato artillery pieces. Here too, however, there is only a finite number of rounds in Nato’s stocks, which have been chronically depleted since the end of the cold war.

Russia hopes that as the Ukrainians burn through the available ammunition, their capacity to resist will wither.

Another challenge for Ukraine is the geometry of its current defences in the Donbas. Russian attacks to the north and south have created a horseshoe of territory still held by the Ukrainian army. After massacres of civilians by the Russian army in Bucha and elsewhere, withdrawal has become politically challenging for the Ukrainian government.

But, ringed by Russian firing positions, it is exceedingly difficult for Ukraine to build up a competitive “fires capability” in the area, even if it had the guns to deploy. Russia appears to be using Sievierodonetsk as Germany used Verdun in the first world war: a point where Russia has firepower superiority but from which Ukraine cannot pull back, ensuring high and sustained Ukrainian casualties.

There are several routes to ending these unfavourable conditions. If the Donbas falls to Russia, the return to a linear front may significantly reduce Russia’s artillery advantage, and if Russia then pushes into Ukrainian territory, the battlefield geometry may be reversed, as occurred north of Kyiv in the early stages of the war.

Another shift from the current attritional dynamic may be caused by the provision of large numbers of long-range western artillery pieces. These, coupled with robust “kill chains”, may allow the Ukrainians to begin to destroy Russian artillery with impunity. Then Ukraine could concentrate its units and begin to press Russia’s inferior infantry hard.

The other method of shifting the current logic is enabling the Ukrainians to build new combat brigades with protected mobility – armoured vehicles for carrying infantry – to enable its units to conduct concentrated attacks from Kharkiv, Kherson and Zaporizhzhia, expanding the frontage that Russia is having to defend. The problem with this is that, to be logistically viable, large numbers of vehicles of a consistent type would need to be provided.

Yet Nato countries – other than the US – not only possess small fleets but have also let many of their armoured fleets become worn out and poorly maintained. Refurbishing these fleets entails time and cost, and it is not yet clear how much cost Ukraine’s international allies are prepared to bear.

The final process of attrition for Ukraine is economic, and in this realm there can be no doubt that it is running out of money, while Russia can withstand western sanctions. Soon it will be essential for economic relief to sustain the government in Kyiv. Alongside the military considerations outlined above, therefore, ending the attritional struggle in Ukraine is ultimately a question of how much Nato members are prepared to invest in Russia’s defeat.

If President Vladimir Putin believes that western commitment may fade in the shadow of a European recession, the risk is that he will be encouraged to grind on.