North Korea has the bomb. Now what?

North Korea's atomic weapon test Sunday night leaves Washington's nuclear elimination strategy on the peninsula in tatters.

This should come as no surprise. For more than four decades, North Korea dedicated itself to getting the bomb. It will not give it up now. To believe that Kim Jong Il will follow the path of Libya, South Africa, and former Soviet states in giving up their nuclear programs is illusory. Once we accept this proposition, we can begin to fashion a strategy to contain the nuclear risk North Korea poses.

During the past two administrations, Washington attempted multiple strategies to turn Pyongyang away from its nuclear course. The Clinton administration tried bilateral engagement and offers of food and energy assistance. The Bush administration tried economic isolation and multilateral coaxing. Neither approach worked, not because they were ill-conceived, but because North Korea immovably associates nuclear weapons with regime preservation.

Compare this case with countries that surrendered the bomb. South Africa gave up following the departure of threatening Soviet and Cuban troops on its border and a desire to end its international isolation. Ukraine, Belarus, and Kazakhstan saw the remnant Soviet arsenals as strategic and economic albatrosses. Feeling the strains of decades-old opprobrium, Libya used the lure of nuclear dismantlement to ensure regime survival and generate economic revival.

By contrast, North Korea concluded that survival requires seclusion, which the bomb preserves. We delude ourselves if we believe that we can reverse what is irreversible. No agreement with Pyongyang will eliminate its nuclear program. And military action against its nuclear facilities is out of the question due to the radiological consequences and the very bloody war that would ensue and envelop South Korea and possibly Japan.Thus, rather than bemoan the failure of past policy, it's time to craft a strategy that copes with this new reality.

A nuclear North Korea presents two challenges: preventing it from using atomic weapons and preventing it from sharing nuclear materials with rogue nations or terrorists.

The first may be easier to meet. The proper strategy is the one we already have in place: military deterrence coupled to the capability to destroy, with certainty, the North by any means necessary in the event it attacks South Korea or Japan. Yes, Mr. Kim is unpredictable. But, despite his bluster, he clearly understands this long-standing US policy, which has deterred his nation from serious military operations against Seoul.

There is a caveat. Nuclear war could still be triggered inadvertently. Take, for example, an intelligence failure. The North might believe, mistakenly, that the United States intended to wipe out its nuclear capability, forcing it into a quandary to use its nuclear arsenal or lose it. Another concern: the North's inability to exercise command and control over its nuclear forces in a period of crisis could result in the decision by a local commander to launch a nuclear strike.

We should implement several measures to reduce these risks. First, establish a crisis "hot line" with the North. Such an emergency communications network served the Soviet Union and the United States well during the cold war.

Second, reduce the North's concerns about surprise attack. For example, eliminate all military exercises near the South/North border and give advance notice of all large exercises anywhere on the peninsula.

Third, provide Pyongyang with low-resolution satellite intelligence of the borderland. Keeping it blind about military activities near the demilitarized zone feeds its paranoia.

Finally, give the North a greater stake in its financial future – and reduce its isolation and paranoia – by encouraging the South's efforts at economic engagement.

Economic intercourse may deliver another benefit. It could abate Pyongyang's incentive to sell military equipment – including nuclear materials, or even weapons – to generate hard currency. However, we cannot rely on this tack.

Accordingly, the US must reserve the right to intercept any North Korean commerce that could provide nations or terrorists with nuclear capability. In the post-9/11 era, it would be imprudent to do otherwise.

Critics of this action plan will contend that it gives in to North Korean blackmail by allowing Pyongyang to retain its nuclear program while providing economic rewards. But because we cannot eliminate its nuclear program without tremendous costs, these proposals are practical. Consider the alternative: a North Korea further isolated, increasingly paranoid, with poor intelligence, placing its nuclear forces on hair-trigger alert, while attempting to get hard currency by selling nuclear weapons to terrorists. We must not allow such a legacy to result from the current crisis.

• Bennett Ramberg served in the State Department during President George H.W. Bush's administration. He is the author of three books on international security.