Yeah, we really can't protect most IP even from just simple reverse engineering. i just worry importing foreign nationals makes it worse.
The only way to stop this would be to go the route of a hypernationalist ethnostate which takes in no foreigners from "rival nations" at all. And in that scenario, the US would need its 340m people to outsmart and outinnovate 1.4bn Chinese and Indians, respectively. With a better education system and many Indians/Chinese growing up in poverty and unable to fully tap into their potential, coping with a 4 times smaller talent pool seems feasible for now - but I wonder if that's still true 20 or 30 years down the line.
Also, what's stopping rival nations from just bribing Americans to do the industrial espionage for them?
Doesn't mean it should be made easy for them; putting up some safeguards is definitely necessary. I just believe that in the long run, some degree of espionage is inevitable.