Technology transfer per se is inevitable. Unless a country wishes to isolate itself from other countries, like North Korea This isn't really about giving technological stuff to enemies or potential enemies which they can then use to harm us - which obviously isn't a good idea - but about trade, and citizens going about their daily lives in a free society with no malice. That's because citizens, institutions and corporations are the creators and disseminators of knowledge and technology, not governments. And even if a government tries to limit trade and all contacts to "friendly" countries it can't control who that country deals with. Or what its citizens, institutions and corporations get up to. Or whether a country later becomes "unfriendly". Truly, the genie that can't be put back in the bottle is disseminated knowledge. Books and scientific papers telling you how to make and do stuff can't be unpublished, business collaborations and takeovers can't be unwound, academic institutions can't be muzzled. A striking example is the Nuclear Boy Scout. More than 20 years ago a 17 yo in Michigan built, all by himself, a rudimentary homemade nuclear breeder reactor in his garden shed just by using library books, legally bought scrap and asking questions. His experiments produced uranium-233 and plutonium and, if he'd not been caught by police on a routine matter, who knows how it would have ended... And there have been others. And there'll be more. All with no malicious intent. Just for the hell of it. Because the knowledge is "out there". But you're right, we can only scratch our heads in amazement that the organized many, with very clear malicious intent against us and serious resources and money to back it, have so far failed to achieve the mass-destruction-of-human-life event that is their ultimate goal. Like you say, they only need get lucky once The gag line in Dad's Army (an old BBC sitcom) sums it up neatly... We're all doooooomed! Dooooomed a tell ye! https://en.wikipedia.org/wiki/David_Hahn