Why Is North Korea Investing In Russian Su-27 & MiG-29 Jets?

According to US officials, Russian compensation to North Korea for supplying much-needed military aid will include early fourth-generation Su-27 Flanker and MiG-29 Fulcrum fighter jets. For now, it is unclear how many will be delivered or when North Korea will receive them. It is also unclear how many service life flight hours these old jets will have ( US-built fighter jets are far more durable, boasting much longer service life flight hours).