One of the problems for the USA might be the overseas aid budget.
The main beneficiaries are:
Russia. Loads of WMD.
Pakistan. Some WMD's
Israel. Some WMDs
Egypt. Strategic, probaly Suez.
So the more crappy joints that get WMDs, the more places Unk Sam has to send money to, to prevent local meltdown and a WMD free for all, which is bad for business.
In fact, as things stand, it looks like a good way of getting handouts.
So N Korea is only following the crowd, an elite crowd of spongers created by uncle sam.