Some 30 years after the dissolution of the Soviet Union, the inventories of many post-Soviet air forces are still very much defined by the Soviet-era aircraft types they inherited. This is especially true for combat aircraft, the expensive price tag of which has dissuaded many nations from acquiring new types to replace older generations currently in service. Instead, proven types such as the MiG-29 and Su-25 undergo overhauls again and again in an attempt to not only keep them flying, but also to keep them relevant in the age of 21st century warfare.