a month before Russia invaded...and they were key to the blunting of Putin's initial attack. A full scale military buildup would have been just the 'Provocation' and justification that Putin wanted While Ukraine lost territory (~11%), after 3 years, it's Russia that was stopped and is now in a full fledged crisis itself.
Link: https://www.npr.org/2022/03/19/1087579496/with-small-portable-weapons-ukraines-fighters-keep-russia-at-bay