When Germany’s military wanted to show off the Leopard 2 in 1986, it turned to the traditional jug of beer.
With a full stein perched on the end of its gun barrel, the 60-tonne vehicle set off along a forest track, hurtling over the rough terrain without spilling a drop.
More than just a party trick, the feat was meant to show how the tank’s advanced stabilisation system would enable it to hit targets while on the move – a vital capability if it was to stand any chance on the battlefield if the Cold War turned hot.
Western military planners believed their tanks would be outnumbered 10 to one in the event of war on the plains of eastern Europe.
Nearly 40 years on, Ukraine is desperate to get hold of the tanks to fight off in a conflict that closely resembles the one the Leopard 2 was designed for.
For months Ukrainian officials, including Volodymyr Zelensky, have been calling for Berlin to donate some of its tanks and let Kyiv’s other allies, many of whom also operate the Leopard 2, to do the same.
One of the German defence industry’s biggest success stories, some 2,000 Leopard 2 tanks can be found in the inventories of more than a dozen Nato militaries.
Their widespread availability alone makes them an ideal choice to help Ukraine’s forces tip the balance against the Kremlin.
While British military officials concede that the Challenger 2s will not be enough to swing the war in Ukraine’s favour by themselves, they argue it is the first step towards creating a “critical mass” of armour that would allow its armed forces to force Russia out of the country.
Tankers believe deliveries of the German-made tank would give Ukraine a much better chance of defeating Russia’s most advanced tanks and breaking through its defences.
The Leopard 2 was developed for the West German army in the Seventies and entered into service at the end of that decade. Powered by a diesel engine, it is equipped with a powerful 120mm (4.72in) cannon and advanced night vision.
It is faster and more nimble than the Challenger 2, but carries less armour.
Justin Crump, a former tank commander with the Royal Gloucestershire Hussars and with 20 years’ experience, said that the comparison was similar to that of a “Rolls Royce versus a BMW”, with advantages to both tanks.
With so many Leopards fielded by Europe’s armies, especially those close to its borders, repairs and maintenance would be easy, with an abundance of spare parts close by.
The Challenger 2, by comparison, requires at least two sets of tools because the turret uses metric measurements and the hull imperial.
The Leopard was designed to be operated by a team of “civilian soldiers,” Mr Crump said.
For example, the Leopard uses single-piece ammo, rather than the warhead and propellant charges being separated, making it easier to train crew as loaders, he said.
Unlike the Challenger 2, the Leopard has a Nato standard 120mm gun, meaning that several countries can supply ammunition for it.
The Leopard 2 “rightly has an excellent reputation around the world,” Ralf Raths, the head of Germany’s Tank Museum, told broadcaster ARD.
However, he warned that it is not an “indestructible game changer” and that its effectiveness will depend on how many are delivered and whether it is supported by the right weapons systems in battle.
He also pointed out that the tank was ultimately never called into service in the Cold War, and as a result, has rarely seen combat.
Germany is expected to announce a donation of Leopard 2 tanks to Ukraine, bowing to weeks of international pressure.
Olaf Scholz, the country's chancellor, is reportedly preparing to send 14 tanks.
Berlin is also expected to allow other countries, such as Poland, to re-export German-made Leopard 2s.
Under international agreements, other countries must be granted permission by Berlin to send their Leopard 2s.
Officials in Kyiv have suggested a dozen nations were willing to donate a total of up to 100 of them, if given permission by the German government.