Complex sentence: Modern terminology mostly uses "spetsnaz" abbreviation to refer to special purpose forces or just special forces, however, the widespread use of this word is actually a relatively recent, post-perestroika development in the Russian language.
Split into simpler sentences: Modern terminology mostly uses "spetsnaz" abbreviation to refer to special purpose forces or just special forces. However, the widespread use of this word is actually a relatively recent, post- "perestroika" development in the Russian language.