U.S. Defense Secretary Donald Rumsfeld said Tuesday if North Korea were to test a nuclear bomb “and were they to proliferate this technology, obviously we'd be living in a somewhat different world.” Secretary of State Condoleezza Rice said the U.S. would have to assess its options if the North carries out the test.

The pair in charge of U.S. foreign and security policy in the Bush administration did not go into detail but indicated that if North Korea crosses the red line drawn by the U.S. with a nuclear test, Washington will take the lead in international pressure and sanctions against the Stalinist country that are far stronger than those imposed so far, including military measures. Japan’s new Prime Minister Shinzo Abe said, “Japan and the world would definitely not tolerate a nuclear test. If the test is carried out, I believe the international community would respond harshly.”

National security aides in the U.S. and Japan agreed Tuesday to meet in Washington and persuade the UN Security Council to issue a statement before stepping up bilateral efforts to manage the risk of a possible nuclear test by the North. The Chinese and Russian foreign ministries also issued statements urging North Korea to restrain itself, saying a nuclear test would damage efforts of the international community to denuclearize.

The short route to eliminating North Korea’s nuclear threat is for South Korea and the four powers surrounding the Korean Peninsula -- the U.S., Japan, China and Russia -- to speak in one voice so Pyongyang recognizes that an actual test would have very serious consequences indeed. North Korea is making such a bold threat because it did not feel the strength of international cooperation when it test-fired its missiles in July this year. The Roh Moo-hyun administration only provided excuses for the missile tests, saying they were “politically motivated” and continuing a variety of inter-Korean projects. As a result, North Korea did not budge an inch even when the UN Security Council passed Resolution 1695 with a unanimous vote in response to the missile tests.

President Roh on Wednesday ordered “cool-headed and firm measures” after the North announced its plan to conduct a nuclear test. It remains to be seen how the government will respond, but as long as there is no fundamental change in the view of North Korea from a president who once said there was “some sense” in its nuclear program, it won’t be easy to stop North Korea’s nuclear program through renewed international cooperation.

As for the “common and broad approach” pursued by the government to resume six-party talks on North Korea’s nuclear program, Roh said in a televised press conference at the end of last month, “North Korea learned of the approach. It has not expressed opposition.” Less than a week later, however, North Korea took us by surprise by announcing it will carry out a nuclear test. Either Roh has groundless illusions about North Korea or Pyongyang has completely bamboozled him.

It was sad to see a high-ranking government official on Wednesday have no more to say than that there is “no fundamental change” in the situation. On Thursday, the government is still to send 6,400 tons of cement to the North, part of 100,000 tons it promised to help it recover from flood damage as scheduled -- not much of a “firm” measure. Cement, as it happens, is an essential material needed to fill up tunnels to conduct an underground nuclear test.

The Seoul-Tokyo and Seoul-Beijing summits next week will be the testing ground for solving the North Korean nuclear problems. If President Roh does not show a cool-headed and firm resolve to friendly heads of state, North Korea’s nuclear program will bring disaster not only to North Korea but also to the South as well.