From Haaretz

Left-wing American linguist, who was scheduled to speak at Bir Zeit Uiversity, given no reason by Israeli inspectors at Allenby Bridge.

The most obvious question that immediately comes to mind is: If Chomsky were not a US citizen would he have ever been given a US visa to enter the country between 1950 and 2000? To get an idea of the atmosphere at the time, the following used to be the questions asked of those wishing to become naturalized American citizens:

Are you now, or have you ever, in the United States or in any other place, been a member of, or in any other way connected or associated with the Communist Party?

Have you ever knowingly aided or supported the Communist Party, directly or indirectly through another organization, group or person?

Do you now or have you ever advocated, taught, believed in or knowingly supported or furthered the interests of Communism?