Back to square one?

North Korea orders UN nuclear inspectors to leave the country.

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North Korea racheted up the tensions over its nuclear facilities. Pyongyang ordered UN nuclear monitors to leave the country. The UN also reports that Pyongyang said it would restart its main nuclear complex, which it had partially taken apart in return for food aid more than a year ago.

And the North defiantly vowed in a statement it would "never participate" in (nuclear) talks any longer." It's harshly reacting to the U.N. Security Council's unanimous condemnation of its recent rocket launch.

EastWest Institute senior fellow Stephen Noerper says Pyongyang is testing the limits.

"They're trying to step it up a level with the idea that this is the first crisis they're putting to the Obama Administration. They want to test the young president. They want in light of improvements of relations of Washington with Tehran and Havana to see if they, too, can be in the new fold. And they're interested in seeing the resolve of the international community," said Noerper.

That community stood firm, with Russia, the U.S., and Japan urging Pyongyang to return to the six-party talks.

The White House called the threat to withdraw from the table a "serious step in the wrong direction."

Spokesman Robert Gibbs said, "We call on North Korea to cease its provocative threats, to respect the will of the international community, and to honor its international commitments and obligations."

The six party members plan to strengthen existing sanctions. Some analysts say the measures won't work unless China goes along, since it supplies the North with food and fuel. North Korea is already poor with a tattered economy. The only way to bring North Korea back to the table, they say, is if Moscow and Beijing pressure the regime.

Fred Katayama, Reuters, New York.