WASHINGTON — Iran and North Korea may be two points on President Bush’s old “axis of evil,” but the authoritarian governments are polar opposites when it comes to defusing their nuclear programs.

North Korea shared secrets about its arsenal of bomb fuel and destroyed part of its atomic factory on television this past week in exchange for economic and political concessions from America. It was an encouraging sign the secretive communist country may give up its bombs altogether and an incremental victory for the kind of old-fashioned, talk-to-your-enemies diplomacy distrusted by Bush administration hard-liners.

But it’s not a sign Iran also can be bought off, regardless of whether Mr. Bush or his successor talks to Tehran.

Weak, poor, and inward-looking, North Korea needs and wants the help the world is offering. Although it remains, with Iran, one of the most heavily penalized countries, North Korea now has won at least the possibility of greater inclusion in the global financial system, and at relatively little cost.

Iran, however, is not such a willing customer.

Strong, rich on $140-a-barrel oil, and widely engaged in the world, Tehran has stiffed European courtiers and a late, heavily conditioned offer of American diplomacy. It has greeted an offer of economic incentives by speeding up its nuclear development work.

Both North Korea and Iran learned an important lesson from other nuclear powers: The bomb or the threat of it is a ticket to international relevance. For both nations, pursuit of a homegrown nuclear program brought tough economic penalties and diplomatic isolation, but also offers from the West and a newfound respect closer to home.

North Korea did not do much to disguise its program, boasted it had the bomb and then proved it two years ago with a crude underground test. The offers improved the closer North Korea got to putting a working bomb on a long-range missile.

Iran’s less-developed program — it has never come close to the kind of test North Korea mounted — would appear to buy time for the U.S. and others that have pledged not to let the clerical government possess nuclear weapons.

“Iran may be a tougher policy nut to crack than North Korea for two reasons: oil and Israel,” an Iran expert at the Carnegie Endowment for International Peace, Karim Sadjadpour, said.

North Korea agreed in principle three years ago to end its nuclear program in exchange for economic and political concessions. Not much has gone according to plan since, but the handover of a long-delayed nuclear dossier this past week is a sign that the basic bargain is working.

“Tough multilateral diplomacy can yield promising results, yet the diplomatic process is not an end in itself,” Mr. Bush said Thursday. He quickly followed up with the promised American payoff: ending some trade penalties and giving notice that he plans to remove North Korea from the American list of nations that sponsor terrorism.

The deal came with major strings.

“They have agreed that every question that we have about their nuclear program — plutonium, uranium, proliferation — is something they have to answer,” a State Department spokesman, Tom Casey, said. “That would mean, if there is any place we want to visit, we should be allowed to visit, any person we want to talk to, we should be allowed to.”

It’s hard to imagine Iran agreeing to that.