So, ICBMs are easy, hm? Just slapp in some smartphone components? Then why is, e.g. North Korea struggling so hard with them? Sure they have access to some Samsung Galaxy 12 over there.
they're struggling with the rockets, not the imus or guidance algorithms. rockets that can launch things into orbit are at the boundary of being physically impossible; if earth was a bit bigger, we'd have to use a different space launch method
It's p̶a̶r̶t̶i̶c̶u̶l̶a̶r̶l̶y̶ pretty hard to obtain guidance systems and components or certain types of ruggedized electronics that haven't been deliberately gimped to prevent them from being used in supersonic or exoatmospheric missiles while on the USA Naughty List, and North Korea doesn't yet seem to have an advanced manufacturing base for this that I'm aware of, whereas Texas or Japan would be a different story.
while this is true, the resulting difficulty is often overstated for both political and historical reasons. itar was conceived in a very different technological, political, and economic world