It seems I've stumbled into a very unique quagmire. Not a single character in my script speaks English, at least, not as a first language.

There is however Russian, Chechen, Bosnian, and Albanian.

I can differentiate the Russian by putting it in italics and making sure to put a note in the beginning about the notation. But what about the rest?

Does anyone else think it would be horrible to read:

Ilia
(in Bosnian)
Saying something profound about being an arms dealer.

Ilia
(in Chechen)
Saying something else profound

et cetera, et cetera?

I guess it's a realism thing in part as I want the dialogue to accurately reflect the region, but in terms of readability, I'm worried that it is an epic, epic fail.

Help!

I would suggest something like this (maybe):

Illia
(in Bosnian)
Profound something
(translation)

Maybe just putting in parentheticals after the dialogue. Or maybe putting in the subtitles in an action line.

As far as I know you should do exactly as you did. You write all the dialog in English (or whichever language the script is written in, and put the language in parenthesis. Then the translators will do their work.
Out of curiosity, where do your characters meet?

They have scores of scenes together in Chechnya where the bulk of the story takes place, but there are also stints in Moscow and Kosovo. One of the characters, however, is a Bosnian from Sarajevo. I think I may have been asking for trouble with this one. ::grin::