The world's top military powers each have fifth-gen jets, but Russia, China, and the US are all facing problems with their fighters

• Russia, China, and the US all have fifth-generation fighter jet programs.
• The Russian Su-57, Chinese J-20, and American F-35 are all facing various challenges.
• Business Insider spoke with several experts about what's been holding these programs back. 

The world's top military powers have been working to develop formidable fifth-generation fighter jet fleets for decades, and that's still a work in progress.

The US built the first fifth-generation fighter, the stealth F-22 Raptor, and it followed that project with the F-35 Lightning II Joint Strike Fighter. Russia and China have the Su-57 and J-20, respectively.