What prevents more countries from creating nuclear weapons?
noodle: iirc, the major issue is that you need some serious money, coordination, and brainpower to make it happen.  many countries just aren't coordinated, rich, or connected enough to make it happen.one of the major inhibitors are, indeed, the "nuclear secrets" as it were.  there are a few special sauces that just take experimenting and tinkering and brainpower to work out.  all of which also cost more and require more supplies.or, at least, thats my simplified, non-physicist understanding of it.