User blog comment:Dean42bean/Dean42bean's Official Quote of the Day Blog/@comment-730941-20100420120522

Burke did say something similar: ""When bad men combine, the good must associate; else they will fall one by one, an unpitied sacrifice in a contemptible struggle."

And according to Wikiquote the Tolstoy line doesn't appear in the original text, but was part of the narration in a Soviet-era film adaptation in 1968.

It's definitely on my reading list when I summon the courage to tackle such a huge novel.