You have to believe that this dog knew exactly what he was doing when he decided to karate kick a cat with whom he was playing. It is an aggressive kick but it looks like play fighting to me. It appears that the dog used his intelligence to figure out that if he wanted to avoid those sharp claws waving around his sensitive nose he should turn around and use his hind legs to kick the cat. And to humans it looks like a classic karate kick. The type you see on television and in films all the time. I am the sure the dog had his nose nicked by a claw at some time in the past and decided to do something about it.
Note: videos on this site are typically made by people other than me and held on YouTube servers or the servers of other businesses (not the server storing this website). Sometimes the videos are deleted at source which stops them working on this site. If that has happened I apologise but I have no control over it.