For conservatives, it has been the war against terrorism. There was terrorism during the Cold War, but we regarded it as a lethal but limited nuisance. After 9/11, though, President Bush said our task was nothing less than to "rid the world of evil."
Before long, he persuaded himself and the country that the effort demanded the invasion of Iraq. The dangers Saddam Hussein and his kind presented, Bush told Czech students, were "just as dangerous as those perils that your fathers and mothers and grandfathers and grandmothers faced." That fantasy led us into tragic folly.
The right has also had trouble shaking the fear of totalitarianism. Lacking the specter of Soviet tyrants, they have found a suitable replacement in Barack Obama, who is routinely, and ridiculously, compared to Stalin and Mao.
Liberals are likewise susceptible to extravagant dread spawned by misplaced nostalgia. For many of them, the darkest time of the Cold War was the McCarthy era, when anti-communist fevers spawned abuses of power and persecution of the innocent. The left has spent the past eight years denouncing a new wave of domestic repression that, in reality, never materialized.
It's no coincidence that the film "Good Night, and Good Luck," about CBS newsman Edward R. Murrow's brave stand against Sen. Joseph McCarthy, came out in 2005. Director George Clooney said it was highly relevant to the present: "We do this every 30 or 40 years; we just sort of, you know, go crazy."
But in the realm of civil liberties the Bush administration, though it often went wrong, did not go crazy. Dissenters were not ruined or jailed. Muslims were not herded en masse into internment camps. While there were instances of indefensible overreaching, there was no reign of terror on the home front.
In reality, we are never likely to face anything comparable to the perils and fears that hung over our heads during the Cold War, and for that we should be immensely grateful. Once was enough. Wasn't it?