Do I italicize Cyrillic book titles in the list of works cited?
In the past, titles and terms in the Cyrillic alphabet were not italicized, partly because it is based on the Greek alphabet, which traditionally is not italicized (on this point, see Chicago Manual of Style, 16th ed., sec. 11.131). Letterspacing instead of italics was traditionally used to emphasize a word or phrase.
Today, Cyrillic cursive (the term italics is usually not used in this context) for titles and for emphasis seems to be used often in publications, including scholarly publications, perhaps because of progress in digital typesetting or because of a global trend toward standardization.
Note that there are many languages in the world that do not have an italic font—Japanese, Chinese, Korean, Armenian, for example. Arabic sometimes uses a typeface that slants to the left instead of to the right.
Given the complexity and specificity of historical, cultural, linguistic, and printing practices throughout the world, a writer should not use italics when a book title is in a foreign language that is not written in the Latin alphabet. If a work is being prepared for publication, let the author pass that buck to the publisher.