They are important to grow crops and graze livestocks. It's the one of the most important sources of food for Russians, Ukranians, Kazakhstanians etc.
There really isn't anything positive for a war at all just mostly negative and the bad things are the following: Lost so many innocent lives, soldiers lost their lives from wars and in camps and prisons, so much money that could've been used for better purposes was wasted on some war, and countries went from allies to enemies even to this day.
It was the Marshall Plan that gave $13 billion to Western Europe from 1948 through 1951. This was a way to make sure that tyrants didn't rise up again.
