It's all voluntary and most of those who enlist do so to (i) try to acquire a marketable skill, e.g., flying a helicopter; (ii) get firearms and marksman background before applying with the Police; or (iii) continue an amateur sports career after college graduation (many free style wrestlers as well as Judokas, and some track athletes are affiliated with the SDF). The very few who want to become career officers will attend the SDF Academy and graduate as first lieutenants.