By purchasing Chinese hardware and getting technical cooperation with Iran.
>> By purchasing Chinese hardware and getting technical cooperation with Iran <<
Yes, those two factors plus enslaving and starving 20-million-plus people in pursuit of virtually a single goal.
As China proved with its own nuclear weapons program in the fifties and sixties, a dirt-poor nation can do just about any “one” thing it wants. Just pour in the resources, to the neglect of almost everything else.
(Moreover, China benifitted mightily from the short-sightedness of Stalin and his successors, who furnished nuclear technology and Soviet advisers to the Chicoms — until Krushchev realized too late what a serious mistake the CCCP had made in this regard.)