i recently read "the bomb in my garden" by mahdi obeidi (sic) who was the head of the iraqi uranium enrichment effort under Saddam Hussein. they started out with nothing and had to do everything from scratch. they were able to spin their centrifuge up to 20k rpm or something like that before it flew apart. you need 50k to enrich uranium. spinning a tube at that speed requires sophisticated machinery and knowledge that can only be gained after decades of hard work. but Saddam insisted that enriched uranium be produced in only a few years in light of the situation with iran. and when he insisted something be done, people would do it or else be killed. and so this required the enrichment engineers to seek equipment and knowledge from more advanced states. its amazing how casual the process of getting these things was for them. at one point they gathered data from a book in the stacks of a college library, a book that was not meant to be lent out to anyone who wasnt willing to provide ID, by simply asking the librarian if she could hand over the book really quick just to be sure its the right book. a lot of the things that stand in the way of people trying to do these things arent super specific but are just things like having the ability to machine metal within a certain tolerance or produce bearings that are within a certain spec. but they they did get their hands on some very important design documents that allowed them to succeed in producing enriched uranium in a very short period of time. its a fantastic book.