The late great Daniel Patrick Moynihan - ambassador, senator, sage and seer - said it when the Soviet empire vanished like a black cloud, and sunshine burst forth everywhere:

History had returned to where it had been before being interrupted by a century-long world war in two gruesome acts and several nerve-wracking intermissions.

Seemingly suddenly, the Iron Curtain was gone and the great division between slave and free states, each armed with nuclear weapons ready to be launched at a moment's notice, was over. The future beckoned, and it looked a lot like a golden past.

We were back to when the 20th Century was young. It sounded idyllic at the time; you could almost hear the Viennese waltzes and bask in an old world renewed. As if good Franz Joseph were still on the throne and the royal families of Europe, all inter-related, would never let anything really bad happen.

All was as it had been before, or rather as we imagined it had been before those fatal shots at Sarajevo, which turned Metternich's Concert of Europe into into Ravel's strange, bitter, death-haunted "La Valse."

Living under the nuclear threat, the world had found it easy to forget just how unstable those earlier times had really been. Blinded by nostalgia, we had not fully realized that, when the old 19th-century swirl of competing nationalisms and radical ideologies returned, it would be even less stable. Because it would be nuclearized.

The seismic shock out of North Korea last weekend should be enough to awaken even the dreamiest out of any romantic reveries about a golden past. Apocalypse is back. And drawing closer with every nuclear blast.

The world's powers great and small seem as paralyzed by events beyond their control as they were in 1914, or in the dithering 1930s. What was a distant cloud, the prospect of The Bomb in the hands of North Korea's Kim Jong-Il, is no longer distant. It's here. And the repercussions of North Korea's nuclear explosion ripple out all around:

South Koreans no longer protest the presence of American troops on their soil; indeed, Seoul now objects when the United States proposes to withdraw our troops, or at least move them back from the flammable border with Kim Jong-Il's mad regime.

Japan must consider not only rearming but rearming to the nuclear teeth - a prospect no one with a sense of history can welcome, including the Japanese.

Communist China's close-to-the-vest diplomacy, which has long served it so well, now lies in ruins. Beijing had sought to preserve a dependent North Korea as a buffer against the example of a prosperous and united Korea emerging on its long border along the Yalu. But now Little Brother is out of control, and soon enough the whole neighborhood may be.

Washington, which has tried everything from appeasement to confrontation to just ignoring the problem, now does little but worry - and relies on, of all weak reeds, the United Nations. Even without Saddam Hussein in power in Iraq, the axis of evil still spins. North Korea has exploded a nuclear weapon, and Iran's mullahs are about to.

At this late date, not all the speeches at the Security Council may help - nor all the irresolute resolutions being proposed. The crazy aunt in the attic is now doing chemistry experiments, and the whole house is shaking.

How adopt a rational policy when confronted with the irrational? What is to be done now that the most precious of commodities in diplomacy, time, has been squandered? Continued...