This would be a good strategy to stop state sponsored attacks, but what about the rest? What about the World Trade Center attacks? The 2002 Bali bombings? The 2005 London bombings?
The WTC attacks were committed by people who were in the country legally, either at the time or they had overstayed a visa. Those attacks would not have happened if the individuals involved weren't granted visas.
Are you telling me I should not be allowed in the USA of which I am a law abiding citizen because of my ethnicity?
Its okay, be strait with me. You won't hurt my feelings.
Perhaps the user is referring to the allegations that US intelligence agencies, using the State Department as a proxy, let people into the US who otherwise would have been denied.
The US is under no obligation to accept immigrants from anywhere. We're under no obligation to be "fair". And yes, I'm telling you we should be keeping a list of countries with significant anti-US terrorist movements and not allowing immigration from those countries. If you're from KSA or Yemen or Pakistan I would not have allowed you to immigrate.