The draft relies on Division O, Title II, Section 203 of the 2016 Consolidated Appropriations Act, which lays out security-related exemptions to the visa waiver program, to derive that list of seven countries. In the 2016 law, Iraq and Syria are explicitly listed, Iran and Sudan are included as state sponsors of terrorism, and Libya, Somalia, and Yemen are in the “area of concern” as designated by the Department of Homeland Security.
What all seven countries also have in common is that the United States government has violently intervened in them. The U.S. is currently bombing — or has bombed in the recent past — six of them. The U.S. has not bombed Iran, but has a long history of intervention including a recent cyberattack.
It’s like a twisted version of the you-break-it-you-buy-it Pottery Barn rule: If we bomb a country or help destabilize its society, we will then ban its citizens from being able to seek refuge in the United States.