To read the seismic signal sent from an abandoned coal mine in the mountains of North Korea's coast, you must first recognize that it represents four major failures, two grave dangers, and one big opportunity.

The apparent explosion of a nuclear device, coming after two decades of trying to stop North Korea from achieving this goal, is a manifest failure of policy on four fronts -- a failure of U.S. nuclear non-proliferation policy, a failure of international diplomacy, a failure of Chinese leadership and a failure of South Korea's strategy of engaging the North.

Having failed so completely, the world now faces two grave dangers. The first is the very real threat of war on the Korean Peninsula, triggered by a series of escalatory actions in the wake of the bomb test. The second is the danger that North Korea will proliferate its nuclear technology, materials or know-how to others -- not the least to another nuclear hopeful, Iran.

But there remains a lone and tenuous opportunity. Having removed all ambiguity about its nuclear ambitions, North Korea may finally have created a common sense of threat that will galvanize the kind of concerted international action that so far has been absent.

THE FOUR FAILURES

Non-proliferation failure

The United States has spent two decades trying to stop North Korea from going nuclear, a turbulent period of crisis and negotiation that even went to the brink of war. At least three administrations confronted this problem and none, certainly not the Bush administration, can escape blame.

North Korea agreed to sign the Nuclear Non-Proliferation Treaty (NPT) in 1985, but it stalled before signing an agreement with the International Atomic Energy Agency (IAEA) in 1992 to place its nuclear facilities under international safeguards and inspections. During that time the North Koreans reprocessed some spent fuel from their reactor into plutonium - an amount that American intelligence believes was enough for building one or two warheads.

North Korea's resistance to full inspections, while it kept pulling spent fuel rods out of its reactor, provoked a crisis in 1994 and led the Clinton administration to ready military forces to strike the North's nuclear facilities. In a last-minute deal, North Korea froze its reactor and reprocessing facilities, effectively halting plutonium production under IAEA supervision. In exchange, the United States, Japan, South Korea and others agreed to construct two light-water reactors for North Korea and to supply fuel oil until the reactors came online.

The deal was troubled from the start. Neither party was satisfied with the compromise or the way it was to be implemented. By the late 1990s, the North had begun a secret effort to acquire uranium-enrichment technology from Pakistan and, in 1998, tested a long-range ballistic missile. Despite this, the plutonium freeze remained in place. But it did not survive the Bush administration.

The Bush administration came into office challenging the value of the agreement and froze contacts with the North. After receiving intelligence showing moves to build enrichment facilities, it confronted North Korean officials at an acrimonious meeting in Pyongyang in October 2002.

The United States halted fuel shipments a month later, and, in early 2003, the North Koreans expelled IAEA inspectors and withdrew from the Non-Proliferation Treaty. They proceeded to reprocess the fuel rods they had stored for a decade, producing enough plutonium, intelligence estimates say, for four to six nuclear warheads. In February 2005, the North Koreans announced they had manufactured nuclear weapons. Last week, they apparently made good on that declaration.

Blame aside, North Korea's emergence as the world's ninth nuclear power may be the most serious failure in non-proliferation history. Unlike India and Pakistan, which remained outside the system of international treaties, North Korea acted in defiance of those controls. Who might be next?

Diplomatic failure

Unlike Iraq, the attempt to stop North Korea's nuclear program has relied on the tools of diplomacy, accompanied by economic incentives and coercive sanctions.

But serious questions have been raised from the start about the sincerity and methods of the diplomatic efforts, particularly on the part of the United States and North Korea. The Bush administration has insisted -- and the president continues to make this argument -- that direct talks with North Korea do not work. Pyongyang has tried to frame everything as an issue with Washington, undermining talks that involved others, including South Korea.

Bush's stance lends credibility to those who charge the administration seeks "regime change," not a compromise that it believes will lend legitimacy to Kim Jong Il. The North Koreans now appear to have used the talks to buy time and build bombs.

Diplomacy has, at American insistence, consisted of six-party talks, held under Chinese auspices and including both Koreas, Japan and Russia. In truth, little real negotiating went on at these gatherings, at least until the last full round of talks in September 2005. In contrast to the thousands of hours of negotiations between Americans and North Koreans that led to the 1994 deal, there have been only tens of hours of actual give and take.

It is intriguing that the September agreement on a statement of principles for denuclearization came only after the State Department's chief negotiator was finally allowed to talk to his North Korean counterpart at length. Even then, their agreement evaporated almost immediately as they dueled publicly over the deal's meaning. American financial sanctions against North Korean currency counterfeiting further clouded the atmosphere, and direct contacts ground to a halt.

China's failure

The North Korean nuclear crisis is also a failure of China's bid for regional, if not global leadership. North Korea is an ally of China, a relationship that goes back more than half a century to the Korean War, when Chinese "volunteers" poured across the border to prevent an American victory. Their relationship has become more difficult since China embarked on market reforms while North Korea clung to its peculiar brand of Stalinism.

China has been torn between its loyalty to Pyongyang, its desire to maintain a stable balance of power in the region and its fear that the North's nuclear ambitions could provoke conflict on its borders. By becoming host for the six-party talks, Beijing stepped into an unusual leadership role.

The Bush administration was eager to move the burden of the North Korean problem onto the Chinese. Some administration hard-liners argued that China had the power to trigger the collapse of Kim Jung Il's regime by cutting off energy and food supplies.

Time and again, Beijing dragged the North Koreans back to the negotiating table, while also pushing Washington to engage Pyongyang in the talks. But Chinese irritation over American inflexibility has now been trumped by North Korea's defiance. Chinese policy-makers now wonder how they can punish the North without creating chaos, or war.

Failure of engagement

The final failure lies on the doorstep of South Korea's 10-year-long policy of engagement. The "sunshine policy" asserted that the North could be induced to give up its nuclear option by opening up the isolated communist state and promoting the forces of Chinese-style reform.

After a historic summit meeting in 2000, South Korean aid and trade, even tourists, flowed into the North. South Koreans lost their fear of a former foe, seeing it more as an impoverished lost brother than a mortal threat. Tensions with their American allies rose because of a gap in the North's perceived threat. The United States wondered why its troops should continue to defend South Korea.

Now South Koreans must confront the possibility that the North may have used engagement only to buy time.

THE TWO DANGERS

Threat of war

With eyes on Iraq and the Middle East, the Korean Peninsula has been far from the center of American attention. American forces based in South Korea and Japan have been dispatched to Iraq.

Yet the demilitarized zone that separates the two Koreas remains the most militarized frontier on the planet, with hundreds of thousands of well-armed soldiers poised against each other. Clashes along that frontier used to be commonplace and there are signs of a renewal of tensions. The danger of unintended escalation cannot be dismissed.

What might happen if a U.S. naval vessel, moving to inspect a North Korean freighter - as the U.N. resolution may authorize - is fired on or even captured, as the USS Pueblo was in 1968? It is a frightening scenario already worrying some at the Pentagon and the State Department.

Risk of proliferation

More than anything else, American policy-makers fear that North Korea, emboldened by its nuclear success and perhaps desperate for funds amid economic sanctions, might sell its nuclear expertise to Iran and others, including terrorist groups.

For Pyongyang, an alliance with Iran is a logical response to American and global pressure. The North Koreans have sold ballistic missiles to Tehran since the 1980s and rumors of nuclear cooperation persist.

An American effort to interdict the movement of ships and planes to Iran -- with possible U.N. backing - is probable. But the most likely transit is across the long and loosely controlled land border with China. The amount of plutonium needed to make a warhead is the size of a grapefruit and hard to detect - creating yet another nightmare scenario.

THE OPPORTUNITY

In this otherwise bleak landscape, there is an opportunity. For the first time, there is a chance of a consensus among the key players -- China, Japan, South Korea, Russia and the United States. The passage of a U.N. resolution is a small step in that direction. But the real test will come next, as the nations must cooperate to put pressure on North Korea, while coolly navigating the perils of war and making sure to leave open a diplomatic exit.

There is a slim chance of such concerted action, and a limited window for achieving it. Not everyone sees the dangers the same way. Signs of rethinking errors of the past are no more evident in Beijing and Seoul than they are in Washington or Tokyo. Ultimately, however, if they are to seize this moment of opportunity, all parties must face up to the fact that the policies of the past have failed.

PESD director David G. Victor testifies to the Senate Committee on Energy and Natural Resources that the U.S.-India nuclear deal currently being debated by Congress could have a large impact on greenhouse gas emissions and be a major step towards engaging developing countries in the fight against climate change.

David Victor shows that by displacing coal-fired electricity generation, the U.S.-India nuclear deal could realize carbon dioxide emission reductions that rival the European Union's efforts under the Kyoto Protocol and far exceed previous efforts to engage developing countries in combating climate change.

For Vice President Dick Cheney, the question of how to deal with would-be nuclear powers in Iran and North Korea is disarmingly simple.

"We don't negotiate with evil; we defeat it,'' Cheney reportedly pronounced, dismissing a State Department bid in late 2003 to make a deal with North Korea. A similar prescription was offered when moderates in the Iranian regime made a secret approach that year to begin talks with the United States.

The long history of the Cold War is replete with the issue of whether -- and how -- to talk with a mortal foe. U.S.-Soviet relations froze time and again. For two decades, there was no dialogue at all with Communist China. But in the end, American policymakers have always chosen the path of negotiation.

For Cheney -- and for President George W. Bush -- sitting down at a table with the likes of North Korea's Kim Jong Il would be an act of weakness, a lessening of American power and prestige that granted undeserved legitimacy to despised regimes.

In recent months, and most prominently last week, the Bush administration has appeared to reverse its stance, opening the door to direct talks with North Korea and Iran.

These moves are carefully constrained, reflecting in part the ongoing divisions in the Bush administration about the advisability of going down this path. Contacts with both regimes will take place only within the framework of multilateral talks and focused solely on the issue of their nuclear programs. One-on-one talks on a broader agenda, including establishing basic diplomatic relations, have been explicitly ruled out, for now.

The decision to talk seems driven in large part by the realization that defeating evil has proven to be more difficult than some in the administration assumed. After Iraq, the use of military force against Iran -- and even more so against a North Korea already probably armed with nuclear weapons -- is highly unlikely. Potential allies in imposing economic and political sanctions -- the Europeans, Russians and Chinese, along with South Korea and Japan -- won't even consider such steps without a greater show of American willingness to negotiate with the evil enemy.

Limited as it is, the significance of this shift has to be seen against the backdrop of deep resistance to such diplomatic engagement in the Bush administration.

"There is a fundamental disagreement over how to approach the North Korea problem,'' explained Richard Armitage, who served as deputy secretary of state from 2001-05.

"'Those of us at the State Department concluded: From the North Korean point of view, the nuclear issue is the only reason we Americans talk with them,'' Armitage recounted in a recent interview with the Oriental Economist newsletter. "Therefore, the North Koreans would be very reluctant to let go of the nuclear program. We knew it was going to be a very difficult process. But you have to start somewhere. You start by finding out what their needs and desires are, and seeing if there is a way of meeting those needs and desires without giving away something that is sacred to us.''

But the White House and others in the administration blocked at every turn their attempts to open direct dialogue with Pyongyang. "There is a fear in some quarters, particularly the Pentagon and at times in the vice president's office, that if we were to engage in discussions with the North Koreans, we might wind up with the bad end of the deal,'' Armitage said. "They believe that we should be able to pronounce our view, and everyone else, including the North Koreans, should simply accept it. This is not a reasonable approach.''

Six-party talks

The compromise was the decision, through the good offices of China, to convene six-party talks that included surrounding countries such as Russia, South Korea and Japan. Administration officials have argued that this format rallies others to back the United States in pressing the North Koreans, effectively isolating them.

The same argument was made for the United States to support, but not directly join, until this past week, European negotiations with Iran. As recently as April, Bush was still publicly wedded to this logic.

"With the United States being the sole interlocutor between Iran, it makes it more difficult to achieve the objective of having the Iranians give up their nuclear weapons ambitions,'' Bush said in answering questions following an April 10 speech. "It's amazing that when we're in a bilateral position, or kind of just negotiating one on one, somehow the world ends up turning the tables on us.''

Arguably, however, the opposite has been true. In the case of Iran, the Europeans, including Great Britain, have consistently urged the United States to talk directly to Iran.

An excuse not to talk

All the other partners in the six-party talks, including the closest U.S. ally, Japan, have held their own direct talks with Pyongyang and pushed the United States to do the same. Ultimately, it is the United States that has found itself isolated.

North Korean experts in the State Department had warned against relying only on this approach.

"In the case of negotiating with North Korea, more is not merrier and certainly not more efficient,'' says Robert Carlin, a longtime CIA and State Department intelligence expert on North Korea who participated in virtually all negotiations with the North from 1993-2000. "The more parties and people at the table, the greater the likelihood of posturing, and the harder it is to make concessions.''

In his view, the insistence on a multilateral approach was initially an excuse not to talk. "They didn't want bilateral talks with Pyongyang and they certainly didn't trust the State Department to conduct any such thing.''

These divisions have persisted. Last September, with the backing of Secretary of State Condoleezza Rice, the State Department's chief negotiator was finally allowed to meet his North Korean counterpart. This led to an agreement in the six-party talks last September, a compromise that conceded in principle the North Korean right to have a nuclear power reactor.

That deal prompted a backlash from Cheney and others, according to senior officials within the administration, and fresh curbs on direct contacts with Pyongyang. But the new proposal to Iran apparently also includes an offer to supply power reactors.

What still has resonance is the belief that direct talks with North Korea and Iran amount to acceptance of the regimes in power in both countries.

Resistant to deal

"Ultimately the president is, on this issue, very, very resistant to the idea of doing a deal, even a deal that would solve the nuclear problem,'' Flynt Leverett, who dealt with Iran for the Bush National Security Council, said in a recent interview. "You don't do a deal that would effectively legitimate this regime that he considers fundamentally illegitimate.''

The administration may calculate that this offer of talks will only serve to isolate Iran and shore up ties with Europe. But it may have stepped onto a slippery slope toward a bargain that will necessarily involve painful concessions to Iran and lead toward a resumption of diplomatic relations broken off almost three decades ago.

Opposition to negotiating with the enemy is deeply embedded in the Bush administration. There is, however, a precedent for a sea change -- Ronald Reagan. President Reagan came to office in the wake of the Soviet invasion of Afghanistan and the American boycott of the 1980 Moscow Olympics. Dialogue with the Soviets was halted and the staff of the Reagan National Security Council opposed any contacts with Moscow.

Reagan himself, in a famous 1983 speech, referred to the Soviet Union as an ``evil empire,'' followed two weeks later by the launching of the "star wars'' missile-defense program. Soviet leaders, we learned later, were convinced that the United States might launch a first strike. In August of that year, Soviet fighter aircraft shot down a Korean Airlines passenger jet that had strayed from its flight path, a sign of sharply increasing tension.

In the Reagan administration, against fierce internal opposition, Secretary of State George Shultz pushed to resume dialogue with the Soviets, beginning with achievable steps such as resuming grain sales. Reagan ultimately agreed, starting down a road that led to the series of dramatic summits from 1985 with incoming Soviet leader Mikhail Gorbachev.

Reagan's willingness to sit down with the "evil'' foe flowed from a sense of conviction in American strength. It is not yet evident that his Republican successor shares the same sense of confidence.