Be afraid, very afraid. Someone somewhere, probably in a French newspaper, is soon going to make a big deal out of the fact that all three U.S. television networks are debuting series about extraterrestrial invasions of Earth. Much as the enjoyable, and perfectly straightforward, “Invasion of the Body Snatchers” has long been reinterpreted as a parable of Cold War paranoia (it was nothing of the sort, of course), so “Invasion” (ABC), “Threshold” (CBS), and “Surface” (NBC) will undoubtedly be viewed as an expression of American unease at the threat posed by the alien civilization of Islamic extremism, and, yes, this [...]