Seoul Called Vulnerable to a N. Korean Attack : Asia: U.S. Air Force chief assesses risks as Clinton tries to ease tensions over north’s nuclear program.

As President Clinton tries to ease tensions with North Korea over its nuclear program, the Air Force’s top general warned Friday that the United States and its allies would be hard-pressed to stop an invasion of South Korea.

Gen. Merrill McPeak said that while the United States and South Korea could defeat the North Koreans in an air war, they might not be able to quickly turn back an invasion of Seoul by ground forces. The South Korean capital is thought to be vulnerable because it lies only 25 miles south of the border between the two countries.

“The worst nightmare,” McPeak said, “is that Seoul would come under attack almost immediately.”

His remarks Friday morning came hours after the President, in interviews Thursday night, once again urged North Korea to permit outside inspections of its nuclear facilities. While holding out hope that the dispute with North Korea could be resolved, Clinton said he had asked the Pentagon to prepare military options should diplomatic solutions fail.

Pentagon officials sought to give assurances Friday that no military action is imminent on the Korean Peninsula and that a review of U.S. troop strength in the region was simply that. But tensions have risen over suspicions that North Korea is close to producing nuclear weapons.

The United States and other countries, along with the United Nations, are seeking the right to inspect North Korean nuclear facilities to check Pyongyang’s claim that its nuclear industry is for peaceful purposes alone.

With sanctions now under discussion if inspections do not proceed, the North Korean government warned Friday that “no coercion and threat can solve anything” and that any sanctions or military moves would be “a big mistake.”

The official Korean Central News Agency described Clinton’s request that the Pentagon review U.S. defenses in South Korea as “a trigger-happy remark intending to push the situation on the Korean Peninsula to the brink of war.”

Meanwhile, State Department officials indicated Friday that some progress had been made during two hours of negotiations with the North Koreans at the United Nations, but White House Press Secretary Dee Dee Myers, traveling with the President in New Mexico, played down such suggestions.

Pentagon officials said this week that U.S. military strategists are preparing several scenarios for beefing up forces along the demilitarized zone.

No concrete steps have yet been taken, McPeak said.

“We in the Air Force are doing absolutely nothing that we haven’t done day-to-day for the last five years,” he said. “The alert state of our forces in Korea has not been increased.”

But McPeak, speaking at a session with Washington defense writers, said the new military planning has led Pentagon leaders to come up with a wide array of possible war scenarios.

One option, he said, is a U.S. preemptive strike against North Korea’s nuclear facilities. He added, however, that such a step might fail to knock out all of Pyongyang’s nuclear arms and could cause radioactive pollution.

McPeak also said that a North Korean attack across the DMZ could result in “a lot of damage” to the South Korean capital.

“I don’t think any amount of U.S. forces on the peninsula is going to change the geography or any reinforcement plan,” he said. “I just can’t answer whether we could stop them before they got to Seoul or not.”

Clinton, in a series of interviews late Thursday with NBC News and the magazine U.S. News & World Report, said he hoped tensions could be defused.

“I still think there’s a chance that we can put (North Korea) in a position where they can crawl back off this ledge they are on, and I certainly hope they will,” he said.

Clinton stressed that while he did not want to raise the specter of military confrontation, Pentagon planners were considering all options should diplomatic efforts become fruitless.