It's customary (and not undeserved) to chortle when the vice president says things like, "We don't negotiate with evil; we defeat it," as he reportedly did in 2003 while discussing North Korea. But, as Leslie Gelb, president emeritus of the Council on Foreign Relations, wrote in Sunday's Washington Post, "the question of talking to villains is hardly simple."

On one hand, it is entirely appropriate, writes Gelb, not only to think of certain governments and groups as "evil," but also to publicly tell the world what you think of them. They will not like it, but it may be effective diplomacy if handled correctly. Gelb traces a lineage of successful diplomacy, from World War 2 through the Cold War, following such bald accusations. But calling bad regimes evil is not the main, or the stopping, point. Gelb's article is titled "Every President Talks to Bad Guys." It's hard to argue the point:

Even as the powerful veep was excommunicating evildoers in his 2003 pronouncement, the Bush administration was cavorting with many of the world's biggest devils: negotiating with North Korea on its nuclear-arms program, with Iran on efforts against the Taliban in Afghanistan and with Libyan strongman Moammar Gaddafi on a historic new relationship. Washington sages are now debating whether to negotiate with President Mahmoud Ahmadinejad of Iran or with Hamas; some are considering trying to reconcile with supposedly repentant Islamist insurgents in Iraq and Taliban fighters in Afghanistan.

Contrary to Cheney's dictum, chest-thumping congressional resolutions and op-ed pieces, the United States almost always deals with devils at some point or another. There is no alternative if a president wants to test nonmilitary solutions to the nastiest of problems. Forget the inevitable posturing. The real issue is not whether to talk to the bad guys but how -- under which conditions, with which mix of pressure and conciliation, and with what degree of expectation that the bad guys will keep their word. When figuring out how to go about negotiating with devils, the questions get very basic.

Gelb is far from naive about what the U.S. will get out of such discussions. We may end up further entrenching the bad guys -- but we can often extract important political and security concessions from them while "exploring the cracks and crevices [among members of the regime] who are disillusioned, tired or just plain ambitious."

"Even devils have interests other than threatening the United States," writes Gelb. "Simply put, if you won't deal with bad guys, don't go into the foreign policy business."