In our war against Islamo-fascist terrorism, we face enemies both overt and covert. The overt enemies are, of course, the terrorists themselves. Their motives are clear: They hate our society because of its freedoms and liberties, and want to make us all submit to their totalitarian form of Islam. They are busy trying to wreak harm on us in any way they can. Against them we can fight back, as we did when British authorities arrested the men and women who were plotting to blow up a dozen airliners over the Atlantic. Our covert enemies are harder to identify, for...