Who said "War between friends is the saddest thing there is."?

This quote is attributed to Mater.

War between friends is the saddest thing there is. - Mater

"War between friends is the saddest thing there is."

Mater War

"I'm a tractor tippin' fool!"

"Dadgum!"

"Well, I'll be!"

"You're my best friend!"

"Some battles are worth fighting."

"Sometimes you have to become the monster to stop the monsters."

"Skynet sent me back through time to kill you."

"War teaches us the value of peace."