After enough T-80s and T-90s got blowed up by Javelins, Western governments eased up and began sending artillery systems and heavier antiaircraft hardware, as well as taking the opportunity to clean out old storage closets of leftover antique armored personnel carriers.
Lately we've been tap dancing up to even heavier gear. The US has announced we'll be sending some M2 Bradley IFVs, and France chipped in some AMX-10 RC heavy armored cars. While referred to as a char, or tank, in French service and apparently some obscure EU regulation classifies anything above a certain weight and with a big enough gun as a tank...and the AMX-10 clears those hurdles...war nerds will insist that unless it comes from the tank region of France it's just a sparkling armored fighting vehicle.
It looks like the inhibition on sending tanks is finally cracking, though. While Germany is still dithering over letting Poland send some of its Leopard 2's, Britain has announced it's sending 14 Challenger 2 main battle tanks.
I found that particular number interesting. Late Cold War and post-Cold War Russian armored units use three-tank platoons and three platoons plus a commander's tank make a ten tank company.
The British Army, from whose stores the Challengers will be pulled, uses some archaic TO&E, possibly left over from the Wars of the Roses or Cromwell's New Model Army, wherein four tanks equal a Bonnet*, and four Bonnets plus two more tanks in a headquarters Bonnet equal an eighteen-tank Spanner†.
Fourteen tanks, however, is enough for three four-tank platoons plus two tanks for an HQ platoon, equalling a fourteen tank US-style armored company. Apparently the Ukies are using a US/(most of)NATO TO&E for their armored units. So the Ukrainians will have at least one company of Western MBTs.
While this is an almost symbolic amount, hopefully Britain's gesture will get Germany off its ass with those Leos. (Ironically, if the West does start sending those Leopard 2s and/or Abrams, the Challenger company is going to be a logistical problem, because the L30A1 main gun on the British tanks is rifled and uses separate bagged propellant charges & projectiles; it's not compatible with the 120mm smoothbores used by the Leo2 and Abrams.)
†Spanner = Squadron