Technically you don't need a degree to be an officer in the UK: you only need A Levels (finish high school) to go to Sandhurst and begin officer training. In reality however something like 98% of Sandhurst applicants are university graduates. I don't know the exact percentage of entrants who don't have a degree though, so don't quote me. It has been a while.

P.s. as a famous example, I believe Prince Harry went to Sandhurst without going to university first.