There are no provisions in the constitution for attaining a warhead.  Yet we allow people to attain automatic weapons – legally – which can do the same damage to human life in a short period of time as a warhead.  We have a constitutional right to bear arms, but there is no constitutional right to human destruction.  The notion of a slippery slope applies equally in the other direction and if one has to choose, they should choose peace over mutual destruction in the name of ideological self-defense.  It is just not that difficult to realize that legislation against automatic weapons is not only appropriate but necessary.