Max Boot is a senior fellow at the Council on Foreign Relations and author of "Invisible Armies: An Epic History of Guerrilla Warfare from Ancient Times to the Present" (Liveright, 2013).

'The dark night of fascism is always descending in the United States and yet lands only in Europe."

That quip from Tom Wolfe is worth savoring as the U.S. prepares to celebrate the Fourth of July—and as overheated rhetoric emanates from fans of Edward Snowden, the proud thief of American secrets. Even supporters, like Sen. Rand Paul, who express discomfort with how he fled to China and Russia, nevertheless applaud Mr. Snowden for alerting Americans to a supposedly dangerous infringement of liberty from the government's monitoring of electronic communications. Mr. Snowden's more extreme acolytes credit him with stopping the rise of a new tyranny in Washington.

Pentagon Papers leaker Daniel Ellsberg recently took to the pages of Britain's Guardian newspaper—Mr. Snowden's megaphone of choice—to discuss the purloining of National Security Agency surveillance secrets. Mr. Ellsberg admitted that the "United States is not now a police state." Yet he claimed that "we do have the full electronic and legislative infrastructure of such a state." All it would take to bring about full-blown dictatorship, Mr. Ellsberg said, would be "a war that led to a large-scale anti-war movement" or "one more attack on the scale of 9/11." Mr. Snowden, he concluded, is saving us from an apparatus that the old East German secret police would approve of, the "United Stasi of America"—in other words, "the FBI, CIA, and NSA."...