Plus the S.300 series is old. The expenditure of them currently by both sides is likely to be high. Stocks have been reconditioned*. That just sounds more likely to result in failures and accidents. (I write as a Googling amateur, of course).*Apparently, Slovakia gave Ukraine its 1990 S.300 battery, which had been refurbished in 2015, and was now near the end of its useful shelf-life.
David Ainsworth ● 942d