With any pod post Napoleon wars, do as much to curb the spread of the latin and cyrillic scripts as possible. Have one or more countries dump the latin script in favor of another.
Is this too implausible? For example, maybe during decolonization, have many African countries reject the latin script as a colonialist influence and instead switch to the Arabic or even Ge'ez scripts. Or maybe they pull a Berber and make their own.
NOTE: While I want to screw both generally, if the choice is nothing but latin vs cyrillic, choose cyrillic. For example, prevent Romania from jumping to latin.