Essentially if they can make the equipment small enough, there could be serious potential for a pure-fusion bomb, which could skirt the test ban treaty as it doesn't fall under the terminology of a nuclear weapon (fissile or fissile and fusion; pure fusion isn't in the CTBT terminology, IIRC).<p>Although the Ares 1 under development is currently capable of putting 25,000KG into LEO, and the Ares V is expected to be capable of up to 188,000KG. So it's not like the equipment has to be exceptionally small if it's capable of producing pure-fusion, it just has to be slightly smaller than the ISS!