why don't they clear out all the ex-soviet tanks in eastern europe and send them all to ukraine? Then the modern stuff can be sent to nato / euro countries to improve things there. Bulgaria, Cyprus, Hungary, Latvia, Poland (obviously), Romania, Slovakia, Slovenia, etc
The Ukrainians know how to use these efficiently. It would be quick to deliver the stocks.
The Germans and the British can then make a lot of money re-supplying their "Allies".