Few statements are as likely to blow up the comments section online as “the F-35 is a trillion-dollar aircraft that can’t dogfight” and “the Su-57 is not a fifth-generation fighter.” The Russian Sukhoi Su-75 has the same potential to ignite a lively debate. But in a world where America is talking about retiring its oldest fifth-generation fighters and is about to test-fly its sixth-gen fighters, Russia is still talking about producing a low-end fifth-gen fighter by the end of the decade.