When will western tanks start to make a difference in Ukraine?

Ukraine has received more than 1,000 tanks from friendly nations since the war began but the deployment of tanks on the battlefield is not going to make a major difference for the Kyiv government until the US Abrams, German Leopards and British Challengers start to be used en masse against the strongest Russian defences. It has been a long time coming and it's not happening yet because the Ukrainians are still training on the Leopards and Challengers, and the Abrams M1A1s won't arrive till the autumn. But if the much-awaited spring counter-offensive by Ukraine is to succeed, these more advanced tanks will need to be in the forefront of the attack. The offensive may have to be delayed. They will need all the tanks promised to be ready for operations but that moment has not arrived. Meanwhile, fortunately for the tough Ukrainian soldiers currently fighting for the survival of Bakhmut in eastern Ukraine, the Russians are proving incapable of mounting any sort of decisive, territory-grabbing operation. The war of attrition is being fought in yards, not square miles. The Wagner Group mercenaries, Putin's private army of prison-released convicts, have failed to achieve what they thought would be a total surrender of the city. The Ukrainian defenders have refused to give in and have driven the Russians into their trenches and ditches. The slaughter toll has been unimaginable on both sides. But the good news for President Zelensky and his campaign to drive the invasion force out of the country is that his soldiers are not in the mood for surrender. They are literally prepared to fight to the death. In Bakhmut it's a noble and terrifying last stand. So if Bakhmut is not taken by the Russians, it will a good omen for when the Ukrainian counter-offensive begins. And with those western tanks, Zelensky's soldiers will have even more confidence that they can beat the Russians.