One year on from the illegal and unprovoked Russian invasion of Ukraine, the West continues to send ever more significant quantities of military equipment and materiel to support the Ukrainians in their fight for freedom.
Following on from pleas from the Ukrainian government, several Nato member states have now announced they will be sending Leopard main battle tanks (MBT), while the US is sending the M1 Abrams and the UK will gift Challenger 2 MBTs.
The latest in our Lima Charlie opinion column series looks at why the donation of Western tanks to Ukraine is so important but also not straightforward.
When the war began, the Ukrainians operated Soviet-era tanks like the T72 and T80 in significant numbers (maybe around 800 to 900).
These older vehicles, a legacy of the Cold War, were cheap, easy to use and maintain and easy to support.
As the war has progressed, estimates indicate that Ukraine has lost several hundred tanks but has been able to capture and bring hundreds of Russian tanks into their armed forces, providing a ready source of spares and equipment.
This has been enough to help the Ukrainian army hold the line against Russian attacks and prevent their achieving any meaningful gains since the early days of the invasion.
As the war has progressed away from an existential defensive battle for survival to one where Ukraine has first fought the Russians almost to a standstill and then begun counter-offensives, the need for military equipment has changed.
The older Soviet-era tanks lack defensive capabilities to be credible in a modern warfare environment (e.g. armour and the ability to stand up against drones and anti-tank guided missiles like the Javelin or Nlaw).
As the war progresses too, Ukrainians will find it harder to secure spare parts and support for their tanks as they draw down existing sources and must rely on captured parts to conduct repairs and refits on Russian designed vehicles.
It is widely expected that at some point in 2023, Ukraine will want to begin a counter offensive that seeks to recapture more land currently occupied by Russia.
To do this they will need modern armour capable of operating as part of an integrated force of infantry, armour, artillery and supporting arms to help attack Russian positions and advance into their territory.
The best way to maximise their chances of success is to be equipped with the most modern tanks and weapons, rather than relying on much older designs from more than 50 years ago (the T72 first entered service in 1969).
The Ukrainian solution is to look to the West to provide them with the most modern generation of MBTs that have been designed from the ground up to fight and destroy Soviet-era tanks.
The Leopard 2 has been the MBT for many Nato nations since the 1980s and has been continuously upgraded since that time.
Armed with a 120mm main gun and capable of speeds up to 70km/h, it is a well-armed, heavily armoured and very mobile tank that reflects German design preferences of the later Cold War years.
Intended to be used to take on large numbers of Soviet tanks in Germany in the event of World War Three, the Leopard 2 has often been considered as one of the most capable MBTs ever built and more than a match for Soviet equivalents.
Following significant pressure from the Ukrainians, about 70 Leopard 2 tanks have been donated, along with 50 Abrams from the US and 14 Challenger 2s from the UK.
This will provide the core of an ultra-modern MBT force that will be well-equipped to go on the offensive later in 2023 and will pose a real threat to Russian forces.
The reason this is such a threat is the combination of extremely modern equipment, far more advanced and in greater numbers than Russian peer equivalents – such as the T14 Armata, of which only a handful are believed to have been produced.
This qualitative superiority, coupled with the reduced Russian stocks of 'smart' missiles and bombs and other effective ways to defeat them will make it much harder for Russian forces to counter the Ukrainian army as it goes on the offensive.
Be in no doubt, when the time comes to go on the offensive, it is likely that Ukraine will be very well equipped – on a par with most modern Nato armies – to hopefully succeed.
There are, though, risks and challenges to this approach that will need to be considered to ensure that the Ukrainian army is properly supported in this mission.
The first challenge is the technical complexity of the equipment being integrated into Ukrainian use.
Their army will need to make the jump from operating legacy Soviet-era equipment to no less than three different designs of western battle tanks in a very short time.
Each of these tank fleets brings a different set of training, logistic and support requirements with them that, in turn, requires different solutions.
This logistical challenge reflects the wider issue facing the Ukrainian armed forces now, which is that they are rapidly absorbing a huge amount of new equipment ranging from the very advanced to the relatively obsolete and they need to be able to properly integrate this and use it in a modern war.
They have emerged with a 'Frankenstein's monster' of a military, cobbled together from well-meaning Western support, but this is not a force that anyone would seek to build from scratch if given the choice.
Ukraine will need to be able to not just operate these tanks but maintain them and keep them supplied with spare parts and ammunition on the battlefield.
The risk is that this logistical and training challenge could put their ability to operate on the offensive under significant pressure, particularly if there are only finite amounts of spare parts or support vehicles delivered.
Ukrainian planners will need to think carefully about how to make the best use of their new weapons to ensure that they can be used and supported properly and not abandoned due to lack of fuel or parts.
One issue which may prove particularly challenging is the problem of how to balance off using these new tanks offensively and the potential propaganda/intelligence coup that will be gifted to the Russians if they capture or destroy them.
In a war that is being fought as much through social media and mobile phone camera imagery as it is with guns and bullets, the propaganda potential for Russia were it to capture and parade a Challenger 2 or Leopard on Red Square is enormous.
The Russians will be keenly aware of this and determined to take every possible step to try to destroy or capture these tanks and secure an information victory in the process.
In turn, Ukrainian commanders will need to balance off the operational benefits these tanks may bring with the risks if captured.
Trying to strike this balance will be difficult because, although likely to bring significant capability to the battlefield, this could come at a high price.
Additionally, with the new tanks available in relatively small numbers, they will need to be deployed with great care.
With only 14 Challenger 2s being sent, the loss or disablement of even two or three represents a significant amount of the force lost.
Are they best deployed in high-threat areas where they will outmatch the Russian forces, or better deployed in quieter areas as a deterrent and a way of holding ground, rather than being lost piecemeal elsewhere?
There is no right answer to this dilemma and only time will tell how capable they are against the most modern Russian vehicles, or if the risks from Russian forces are overstated.
Nato nations also face a dilemma, too, in working out how much support to send Ukraine.
Over the last year, they have been incredibly generous in providing spare parts, equipment, munitions and weapons to Ukraine, but these stocks are starting to run low and replacements will be needed.
The difficult political balancing act is working out how much more can be given versus how much needs to be held back for national defence needs.
In the UK there has been a lot of media coverage about the drawing down of British Army shells and ammunition to support Ukraine, which will take several years to fully regenerate.
Is it better to give this to Ukraine to use this now against Russia, knowing that this could make a material difference in holding back and defeating their armed forces, or to hold it in reserve to provide munitions to deter Russia from attacking a Nato member?
As the war progresses into its second year, the question of the level of support that can be offered will become increasingly important.
Nato needs to be realistic in what it can provide and ensure that its own capabilities do not become too reduced.
However, in backing Ukraine, they also have to be ready to go 'all in' to ensure that Russia does not win on the battlefield – the worst possible outcome for Nato is a Russian battlefield victory that brings them within striking distance of Nato member states, particularly if these countries are short on ammunition and equipment to defend themselves with.
It is perhaps helpful to think of Ukraine as a battlefield on which the West is taking a strategic bet by helping to prevent Russia from posing a threat to Nato directly, but in doing so is also running a potential risk that if the bet fails to pay off, then Russia could pose an even greater security risk to the West.
Another challenge Nato will need to consider is what does the impact of these donations have on their own national military plans?
In the UK, for instance, the Challenger 2 force is being upgraded to the Challenger 3, with current plans calling for 148 of the roughly 227 strong force to be upgraded to the new standard.
This programme requires vehicles to be upgraded and spare parts cannibalised from other donor vehicles not being upgraded to help complete the process.
The move to donate Challenger 2s to Ukraine will reduce the number available for use in the British Army in the short term and also reduce both hulls and spare parts for use in the Challenger 3 programme longer term.
If the UK moves to donate additional tanks to replace combat losses (something that UK Defence Secretary Ben Wallace has already hinted is a possibility), then this places even more strain on the future of UK tank plans.
The UK will, at some stage, need to decide when it can no longer provide vehicles and parts to support Ukraine, because to do so poses an unacceptable risk to the needs of the British Army.
But can the UK claim to be a prominent supporter of Ukraine if it isn't prepared to do, or give, anything and everything in this fight?
The long-term impact of this dilemma may pose substantial problems for the Challenger 3 programme and in turn, the ability of the British Army to maintain an armoured force into the 2030s.
But is it better to use the vehicles now to not only help Ukraine, but also materially reduce the overall size of the Russian stockpile, knowing that every modern Russian tank destroyed now is one less to threaten Nato in years to come?
Perhaps the biggest dilemma facing Nato is knowing when to draw the line on providing support.
Right now, Ukraine is rightfully receiving aid to help defend against Russian attacks, but can this stand up in the longer term?
The Ukrainian government is clear that its war aims are for the liberation of all Ukraine's recognised territory, including Crimea, which was annexed by Russia in 2014.
The defence of Crimea is almost certainly going to be a 'red line' for the Kremlin under which it would consider using all the weapons in its arsenal to defend at any price.
While Nato member states are comfortable supporting defensive and some counter-offensive operations, would they be willing to support an attack on Crimea knowing the potential consequences of such a move?
This may prove an operation too far for Nato, who could withdraw their political and operational support if they feel that Ukrainian activity is posing a bigger risk to European security as a result.
This could lead to a challenging scenario emerging whereby Ukraine launches an offensive using Western equipment without support or supplies and has to fall back – potentially against a galvanised Russian resistance.
Can Nato take the risk that by stopping support for a recapture of Crimea, that the result may, in turn, lead to Ukraine being defeated elsewhere?
The overall situation remains incredibly complex, fast-moving and unclear.
As the war continues into its second year, the level of support from the West remains high and the Ukrainians continue to demonstrate an excellent capability to learn and use advanced equipment to good effect – just look at the way they have incorporated all manner of diverse Western equipment into their military in under 12 months and are now using it effectively in the field.
At some point though, as the balance shifts and Ukraine goes from the defensive to the offensive, difficult decisions will need to be made in capitals across Nato about whether the line for continuing support has been crossed and, if so, what that means for longer-term support for Ukraine.
While tactically the provision of modern tanks will make a huge difference, in the medium term there are serious strategic policy dilemmas ahead for Nato because of this decision.
This article is the latest contribution in our Lima Charlie columnist section.
This is part of a series featuring unattributed contributions from experts and insiders providing opinion, insight and analysis on today's Armed Forces, the wider politics of the military and observations on military life.
Under the pseudonym Lima Charlie, our contributors aim to explore the issues facing the military and their comment remains unattributed to allow our writers to present their analysis candidly and under one editorial voice.