U1 provides cover to get material to Iran. Once it is out of the US, seems it would be pretty easy to lose track of.
I kept thinking Pakistan, but there is little news out of there.
So here's my theory so far:
Obama's Iran deal provides $33B to Iran and no real controls on (3rd party?) nuke development.
ES provides rocket tech and/or nuke tech to NK (their launches escalated and improved drastically after ES visit as did their nukes).
Iran pays NK for development (pays and/or holds them hostage with info?)
NK provides nuke/rocket tech to Iran (designs, not actual rockets)
Does this mean US is the "rogue nuclear state" mentioned earlier?
If so, just wow. But it fits with timeline and makes sense in terms of how they think.