Letter from the editor.

• Author: Rebhun, Elliot
• Position: Editorial

Our cover story focuses on one of the biggest challenges facing the U.S. and the world today: the possibility that rogue nations--with Iran and North Korea only the most prominent--or terrorists could get their hands on nuclear weapons.

In a way, according to Times White House correspondent David Sanger, the nuclear threat is scarier today than it was during the Cold War when students hid under their desks during air-raid drills. At least then, Sanger says, we could be sure who our enemies were.

Upfront will return to this topic in the spring with a Times Past piece on...