:Actually, that's an urban legend.  It's not a matter of diacritical marks, but of letters that were eliminated by the spelling reforms of the revolution.  Before these reforms, "peace" and "world" were spelled differently by one letter, but ordinarily pronounced in the same way.  After the revolution, they were spelled the same.  And if you look at an old copy of War and Peace, before the spelling reforms, it's clearly "peace," not "the world."  The legend doesn't really make sense when you realize that War and Peace was well known internationally, under that name, for decades before the spelling reforms, when the spellings were distinct.  It may be true that Tolstoy intended it as a pun, but the title as published is definitely "War and Peace."  Here's a picture of the first edition: