Yes. And Ukraine has been doing that by releasing videos like this: https://www.independent.co.uk/news/world/europe/drone-russia...
Ukraine can make Russia look bad by killing Russian troops (which also has the side-effect by making those troops run away, offering more security to Ukrainian cities).
Explain to me how killing people in Belarus helps Ukraine, more so than killing the Russian invaders and further demonstrating the corruption and incompetence of Russian troops.
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We know why Russia would want to attack Belarus. Belarus originally promised to attack Ukraine, but has been holding back for some reason. Russia has clearly decided it needs to "encourage" Belarus into attacking Ukraine.
Ukraine, who already has a significant number of Russian troops to deal with, has no desire for Belarus to join the fight.