American immigration policy towards Israelis is essentially the same as towards anyone else. My (Jewish Israeli) coworker from grad-school wanted to work for Google in Mountain View, but the company couldn't swing him a visa. He stayed at Technion to do a PhD.
He now says that he doesn't want to come to the USA with Trump in power.
You tell me how a Jewish Israeli computer scientist poses a threat to the United States. And if you think you can, be aware that I'm such a person, on top of being American, so you had better explain to me how I'm a foreign threat to my own home country.