Is this true or is my recruiter full of it?

I contacted a recruiter for the air force and told them I was interested in joining. Within a week I had an offer for a job. Not even fully realizing what the job was (but THINKING that I understood it fully), I said I would take it. I realized I made a mistake, and was told that you can ask for a different job. So I asked to wait for a different job. I didn't ask to be dropped from DEP, only to be dropped from this particular job. At this point it wouldn't have to be a cool job, just not one THIS dangerous (I picked the most insane job apparently), I'd take any simple service job, maintenance, whatever. But now this recruiter says if I ask for another job they'll drop me. Can he do that? I mean that seems strange to me, to threaten to drop someone if they don't want to take their first job offered to them. Aren't you entitled to pick a job (or wait for a job) and not be held to one job? I haven't left yet, surely they could find someone else to fill this spot. I know that I messed up, whatever, but since when do they force you into jobs? I have to choose between going into this job or just forgetting it altogether. Opinions of this aside, CAN THEY DO THAT?