Why are Tajik and Ossetic written in modified Cyrillic scripts?

During and after the Soviet era, Tajik and Ossetic were written in modified Cyrillic scripts as a result of the language and nationality policies implemented by the Soviet Union.1

Throughout the Soviet period, the government promoted Russian as the primary language of administration and intercourse across its republics. To facilitate this, the Soviet authorities mandated the use of modified Cyrillic alphabets for many non-Slavic languages, including Tajik and Ossetic. While these languages had previously utilized other writing systems—such as the Perso-Arabic script for Tajik or the Georgian script for Ossetic—the adoption of Cyrillic was part of a broader effort to standardize writing systems and align them with the dominant Russian-based script used throughout the U.S.S.R.23145